Understanding how features of one app translate to another is crucial to a smooth transition. I built sites for years in iWeb; it empowered me to put sites up in ways I'd been unable to do before. When it became clear that Apple wasn't going to continue to support iWeb, I searched for and found an able replacement: Sandvox. But the hardest app to learn of any genre is your second one, because you're always comparing it to the first one, and clear answers don't usually come without a lot of digging. Here's what I discovered about several differences between iWeb and Sandvox:
Both Sandvox and iWeb allow you to have multiple Inspectors open at once. This saves time because you don't have to flip back and forth between tabs on a single Inspector. The only difference is the way you do it: In iWeb, you hold down the Option key while pulling from the Inspector tab bar with your mouse, which "tore off" a new Inspector. You do the same in Pages, Numbers, etc. If you're used to this method and try it in Sandvox, you might think that Sandvox doesn't allow multiple Inspectors, but it does. From the menubar, go to View>New Inspector. I typically keep these inspectors open:
Column 1: Page Inspector - Page tab, Page Inspector - Appearance tab
Column 2: Page Insepctor - Collection tab, Wrap Inspector, Text Inspector
Column 3: Metrics Inspector, Link Inspector, Object Inspector
I keep these three columns of Inspectors to the right of the screen. This leaves room on my MacBook Pro 17" screen for a large window showing the domain I'm working on.
If you want to use AdSense ads in your website, you need to use Raw HTML objects in both iWeb and Sandvox. But I've requested this as a Sandvox feature, and based on Karelia's track record, I'd say there's a high likelihood you'll see AdSense Objects before too long.
iWeb had a search box on the blog (that searches only the blog,) but none elsewhere, or at least not in the template I was using. Sandvox has no built-in search engine, but that's OK because Google has a very good (and free, if you choose) search engine described in this post. You can have several different search engines on a site, and in different locations. For example, Mouzon Design has a search box at the bottom of the home page that searches the entire site. It also has a Mouzon Design Blog search box that searches only the blog, and a TA-TV search box that searches only the video channel (or more specifically, the text on the video posts.)
Desktop Publishing Object Placement
iWeb allows you to place objects wherever you want on a page, much like you might do in a desktop publishing program such as InDesign. Sandvox is more structured. In the Wrap Inspector, you have to decide whether an object is Inline, a Callout, or in the Sidebar. Here's what those terms mean:
Inline objects move with text, so if you add text above them, they move down the page. You can choose to wrap text around inline objects or not. Inline objects can be left-justified, center-justified, or right-justified. Just drag them to one of the three positions. Problem is, you can't drag them anywhere else.
Or at least I thought that was a problem when I first started using Sandvox. But the limitations also create predictability. With my iWeb sites, stuff that I placed in a particular position would jump around on the page depending on the browser it was viewed in and the fonts on the computer. With Sandvox, I've never had that happen. No text obscured by sliding objects and therefore unreadable. No design that looked great on the screen but was broken online. So I'm now of the opinion that Sandvox's layout limitations should actually be considered a feature, not a problem because everyone can see your design the way you intended it on their browsers.
Main Body Outline - Or Not
iWeb builds a page with text objects, graphic objects, and widgets. Each text object, when selected, gets a hairline outline. The iWeb page is composed of the header, which has limitations, and everything else under it, where you can place objects as you like, as noted above.
Sandvox has a header, a main body, a sidebar, and a footer. Objects within each of these four areas get outlines and handles when selected, like you'd expect on any Mac program, but the four main areas themselves do not. Sandvox considers them to be inviolate, and therefore immune to manipulation. In other words, grabbing their handles and pulling wouldn't accomplish anything, and would therefore be annoying.
This grated on me at the beginning, because I wanted to be able to grab everything and modify it, just as I'd do with a text box or graphic box. But now I see the wisdom of not including an outline or handles on something you cannot change.
Text Wrap Margin
iWeb allows you to vary the margin between objects and the text that wraps around it. Sandvox does not (at this time.) Sandvox should. But the great thing about Sandvox is that Karelia (the company that publishes Sandvox) is really open to conversation, and you can talk to lead engineers and even the owners of the company on occasion. Try that with Apple (which I dearly love, but not in this regard.)
Already, Karelia has made a number of modifications to Sandvox because I asked them to. Try that with Adobe, Apple, Microsoft, or any of the big boys. This isn't to say that others weren't also asking for the same modifications off-list, but it's a great feeling to ask for a software feature and actually get it within a few weeks or less.
This was always a downside with iWeb. It had only a handful of upgrades in its entire lifetime, with the final one having occurred with iWeb 09. Karelia upgrades Sandvox every month or two, and if you participate in their beta testing program (I do) you get beta upgrades every few days. It's great to work with a program that's obviously alive and improving all the time, IMO.
iWeb can set the format of links, set the content width, header height, footer height, page background, etc., within Inspectors. Sandvox can accomplish exactly the same thing, but you have to do it within the CSS. As noted elsewhere, I've had the best luck using CSSEdit.
Formatting Blog Home Page
iWeb is better here, but Sandvox isn't so far behind. With iWeb, you can click on the Blog Summary on the blog's home page and it will let you adjust several variables concerning the text and graphics of the blog summary. Sandvox does a similar thing, but with what is normally the Object Inspector. Go to a blog or collection's home page, click on the Titles & Summaries object, and the Object Inspector will transform into the Titles & Summaries Inspector where you'll have many of the same options (but not all) as you do in iWeb.
iWeb allows you to drop objects into the header, whereas Sandvox is more restricted. You can, in Sandvox either have a text header, with or without logo and/or tagline, or you can do a banner graphic. Here, I can't think of an upside to Sandvox's restrictions. OTOH, I can take any iWeb header and transform it into a banner by taking it to PhotoShop and making a graphic out of it.
There's a common expectation on the internet that you should be able to click on the site banner, or at least the logo, and it should take you back to the home page. iWeb can do this. Sandvox can't. At least for now. But I've asked for it a couple times, so check back soon and see if they added this feature.
iWeb allows you to drag objects into the footer as well as the header. Sandvox only allows you to either show the footer or not. Fortunately, the footer is one of the least-read parts of the site, so while my inability to edit this part in Sandvox is annoying, it's not the end of the world because few visitors ever read the footer.
Both iWeb and Sandvox can format some characteristics of text in the Fonts window. iWeb has more capabilities. The only downside is that the more heavily formatted text may not translate so well t0 many browsers, especially the old ones.
iWeb can do many things to an object, including adding shadows, reflection, and opacity. Sandvox can't do nearly so much, but the Sandvox objects look more consistent across many browsers.