I might be a little late to this party, but I'd like to add my two cents.
I've owned the TF201, the TF700, and the Galaxy Note 10.1 (along with the Lenovo K1, Sony Tablet S, Galaxy 7 Plus, Galaxy Tab 2 7", and the Nexus 7). I buy/sell/trade them all through craigslist, use them for a few weeks, and then punt them. After trying all of them, I keep coming back to the TF201.
I don't understand why the Prime gets such a bad rap. Yes, the GPS is unusable. But otherwise, it's an awesome device. It's the thinnest of the bunch, the aluminum backing makes it feel super-strong, and the display beats everything out there besides the TF700. But the lower resolution screen translates into a faster tablet because the processor doesn't have to push all those extra pixels. So the TF201 is actually faster in some respects than the TF700. Asus provides as close to stock Android as you're going to find. And the docking station really does add a different dimension to either Asus tablet.
The Note 10.1 is a really nice looking device, the S-Pen is cool (although I didn't use it much), and the front facing speakers should be built into all future tablets. But, Samsung skins the hell out of the device and the plastic back make the tablets feel really cheap, especially when compared to the Transformers. The Note 10.1 can be rooted and I think the dev community is pretty strong, but the Asus dev community is probably stronger imo.
So, to sum it all up, I'm still partial to the Prime. I'm dying to get my hands on the Nexus 10 because I assume that's the best of everything right now, but $400 is too rich for my blood right now and I haven't been able to score a used one on CL yet. I'm also scared away because I really like having an option for expandable storage. But, it's only a matter of time before I find one. And probably by the time I get one, a newer/faster/better tablet will already be released.
Good luck on your search. I hope this helps.