Also, 3D is a product name... when this was first released, it had no stereoscopic support and was as much 3D and sense "3D" is 3D. That is, it has a 3D look to it but not 3D as we "true 3D" phone users like to think of it. It's marketing and there are lots of "3D" applications out there that have no stereoscopic support of any kind. Don't get fooled by those, either.
BTW, I'm a longtime SPB shell user under Windows Mobile. I've looked, briefly, at the shell on Android and while it's nice, and SPB has always done a top-notch job, I don't see significant advantages, for me, over Sense.
A few advantages for SPB Shell, and you may or may not care about these:
1: It's more customizable than sense. Even the shortcuts on the bottom (where Sense has the phone, personalize, etc) can be changed to whatever you want.
2: You can have as many panels as you want. So I can have a panel full of shopping apps like ebay, amazon, best buy, etc. And another panel full of music apps like Pandora, tune in radio, etc. And as many or as few panels as I want. It's not like sense where you're stuck with a certain number of panels.
3: Better widgets than Sense. For example, it has a battery widget that has a little battery picture showing you how much is left, and it has the percentage under it. If you tap it, it shows you your battery usage. There are a bunch of pretty sweet widgets, but that is one example (plus you can still use the Sense widgets too if you're on a Sense ROM).
4: Landscape support. Shell 3D now has landscape support. You can set it to portrait, landscape, or auto.
5: Eye candy. Shell 3D looks much nicer than Sense. It has semi transparent icons that look awesome when you select a cool background (which is easy to do using the flickr widget or even the HTC backgrounds). Not only that, but it has a bunch of widgets that are just incredible to look at.
So you may or may not care about any of those things. But I have a hunch if you try it out for a couple days you will not go back to Sense. I used Mobile Shell on Windows Mobile too and while this is similar in a lot of ways, it's way better. Or maybe it just seems way better because the phone is way better, hard to say. Either way, Shell 3D was awesome on my Evo 4G, and much better on my Evo 3D, especially this latest version.