I really like the UCD airplanes. I've had the 60 and the 46. I think the 46 is a better flying airplane but I like both of them, a lot.
The 60 is very nice with a Saito 100. If you use 30% fuel it's very VERY nice. It's a great plane and I love flying the UCD. I've had many "so call nicer" airplanes but I don't think I like them better. The UCD is sooooo much fun to fly.
The problems with this plane:
1. The fuel tank is a little high and the engine will tend to leak fuel when not running. It's not a performance problem, just messy.
2. Very light airframe. This is good and bad. It makes the plane fly nicely but it is a bit fragile. But I don't think any more so than most modern 3D planes.
3. The landing gear block is weak. Almost everybody that has this plane breaks it out sooner or later. But the good news is you can glue it right back in. It's an easy fix.
4. This plane is not known for it's Knife Edge capability. I can do them all day long but it is harder than on some other planes, namely, The Yak or the Showtime just to name a couple. You either have to be good on the sticks or use a lot of mixing to get it to do a good KE.
5. I'm also told (can't do them pesonally) that the wing design of the UCD doesn't allow for good rolling harriers. It will do them but again not as nice.
6. Also, the Harrier maneuver isn't as nice as some.

On the positive side:
1. One of the funnest planes you'll ever fly.
2. Will do any 3D manuever just not as nice as some.
3. Hovers easier than almost any other plane.
4. Super easy to fly and land.
5. Very light, high perfomrance airframe.
6. The best visual detection of any airplane I fly.
7. Inexpensive for what you get.
8. Very good support and availability.
9. Flexible for engine combo. Very good with Saito 100 and 16x4W prop. Excellent with YS 110 and 16x6 prop.
10. Truly a nice 3D airplane. I've had two 60 and 5 46 sizes. They inspire so much confidence that I'm willing to try anything with them. Obviously I can't do it all. But I haven't crashed them recently.

Seanychen even has one of these with floats. Very flexible airframe.

This is one plane I will always replace and never be without. It is truly the plane I have the most FUN with. And for me, that's what it's all about.
Hope this helps.
Thanks
Barry
PS: theres a thread on the 3D forum about the 46. Over 3000 posts. You are welcome there and will get great information about the 60 airplane on that thread as well. Just ask any question you want. You'll get answers.