I have both and the Diablotin may be the better choice BUT:
The wing tips on the Diablotin will be crushed when you get it. I've seen it on 2 of them.
They are usually on backorder and take awhile to get.
If you get one securly mount the horizontal stab supports. One of mine pulled out and half the stab and elevator went bye bye.
It's built so light that it's more fragile.
The instructions consist of a 8.5X11 drawing of the plans. No text.
It takes awhile to put together and needs ALOT more thought than the UCD.
The wing won't fit in the saddle because the dowl hole is off on the fuse.
Landing gear and wheels are worthless.
No motor mount or tank. Take the included hardware and throw it right in the garbage.
The plane does fly slooooow and 3D's good. They are cool planes. My avatar has a pic of mine before it's mishap. I still have it and can fix it but I haven't had the motivation.

The UCD is a little more user friendly, can't fly quite as slow but slow enough, has alot better knife edge. Both plane hover EXCELLENT. UCD goes together ALOT easier and ALOT faster.