I've been trying out Go Launcher EX. I've only noticed one slight disadvantage of this under Touchwiz, namely that it's slightly harder to move icons/widgets from screen to screen as you can't do TouchWiz's fancy tilt-the-phone-to-switch-pages trick.
There are several advantages that make me really prefer Go Launcher:
(1) You can resize *any* widget - most useful for scaling down needlessly big widgets.
(2) You can adjust the number of icons/page. Adding an extra row works nicely for me -- the extra space is handy, and it's not too crowded on the E4GT's huge display.
(3) You can adjust the transitions as you flip from screen to screen. A lot of the options are too frenetic for me, but a few, like the ones that make it seem like you're spinning a cube or a windmill, are pretty cool.
(4) You can rename all your icons and/or associate new images with them. There are a lot of custom themes available for free or cheap that can give you a lot of thematically similar icons. (That's actually not attractive to me, as I like my icons to look way different so it's easy to find the one I want, but I'm sure other people will rank aesthetics over functionality, and this gives you a lot of aesthetic options.)
(5) Your dock (the fixed bottom row of icons) gets up to 5 icons, plus you can swipe it left or right to get up to 10 extra dock icons if you want.
(6) The dock and app drawer can get their own backgrounds (also available in themes).
It may be that you can do some of this on TouchWiz too, and I just didn't notice how. As for other popular launchers, I think they can do a lot of this stuff as well, so I'm not sure how many of these advantages recommend Go in particular.
The main feature I currently wish Go had is the ability to overlap icons/widgets, so I could, for example float a clock over top of a map showing which parts of the world are in daylight. Oh, and I'd love to be able to get rid of the dumb home button out of the app drawer, as my phone already has a home button that I'm well-trained at using -- duh! But these are pretty minor wishes, and TouchWiz wasn't any better.