Fastplane,
I woulnd't say the US is a lesser setup, just that it's different.

Between the US and the Funtana, they are both easy to fly when set up right. I said the US is a little easier mostly because it should be easier to set up, and I think it's a little more stable (don't worry, it's not trainer-like-stable though). The Funtana is designed to be at least passible in 3D, that means it has really big control surfaces. Larger control surfaces require better control linkages to avoid flutter and so on. But as long as you don't set up for the "3D rates", it will fly just like most sport planes, and the linkages will have enough mechanical advantage.

Also, many 3D planes don't take well to roaring around at high speed. They are designed for slower flight. Though there is a guy with a Funtana 90 at my field who flys it pretty fast, and pulls pretty hard in turns and loops (I'm surprised he hasn't pulled the structure apart yet). The US is, I think, built a bit stronger and will handle high speed flight a bit better. But the US isn't designed for 3D either, and it might not knife edge as well as something with a bigger fuse. (I haven't tried knife edge with the US, so I'm not sure)

Lots of options out there, and lots of trade offs. The good news is that there aren't that many "bad" options, just different options depending on how you want to fly.