Mark,
I hear lots of advice here in this thread about whether or not to move on to a Hype, UCD, or similar plane. I did in fact go from a Kadet Senior which is the worlds easiest airplane to fly to a UCD 60 size and it was an easy transition. BUT, if you do decide to go that route here is my opinion.
Before you graduate to a UCD type plane you should be able to Take off and land well, I mean no fear of screwing up and stalling on approach or getting confused with the plane coming at you. You should be past that point. If you still get a little confused at times during routine flying tasks dont move up yet. If you can take off, fly around, do a few stunts and land without having to really concentrate on what you are doing for fear of getting confused you should be fine. If not dont move up to a UCD or anything else for that matter, a symmetrical winged plane is as easy as a trainer to fly, if IF you are truly proficient at basic flight. Difference is they are not forgiving, they go where you point them and will stay at whatever attitude you put them in until you tell them to do something else.

The UCD is a very easy plane to fly at low rates and is not prone to stall. I have flown all sorts of airplanes now, and in my humble opinion the UCD may be the easiest to fly symmetrical winged airplane there is! As a matter of fact if there is the slightest breeze on landing it will not want to set down because the wing loading is so low with the recommended size engine, the UCD is a real floater and it is extremely difficult to stall. I found it difficult to make a standard approach and landing, mine has to slow down to almost a stop and make more of a harrier landing. Once I upgraded from a .91 and crammed a Saito 1.2 and and a big battery pack in it and increased the wing loading it started making more conventional landings with some airspeed at touchdown. And now it is a 3D BEAST!

This guy who didnt like the Hype, must not be a real good pilot because the Hype is arguably the most 3D capable of all the 46-60 size planes. My UCD is really nice and it flies like a trainer or is capable of some VERY violent or very cool 3D maneuvers and you will LOVE it, but it doesnt 3D quite as "pretty" as the Hype.