Hi Tony and welcome back to the addiction.

I own the Extra 300S Gene Soucy version (160 size) and have flown the UCD 60 more than once using a Saito 100.

The Extra when using the OS160FX and an 18x6W prop is a beauty to fly and does pattern and IMAC sequences very well with very little pitch coupling and no roll coupling at all and can slow to a crawl when landing. It is said it can 3D and I have been able to with mine but when compared to the UCD it's no contest. The UCD blows away the Extra in 3D.

In my expereince flying someone elses UCD it is very stable at super low speeds and a very nose high attiude. I did the first hover on this plane and just came down the runway really slow, added a couple of clicks of power and full elevator and stood it right onto it's tail. I got it to do great parachutes, waterfalls, inverted flat spins, blenders and KE spins and when I landed it I probably would have been able to walk along right with it. It does IMAC sequences well, but not as good as the Extra (two very different planes), and I never tried the FA3 sequences on the UCD. The UCD does have a good amount of pitch and roll coupling but nothing you cannot mix out with a decent computer radio or just fly around it if you desire.

So if you want decent 3D, sport and fun flying get the UCD. If you want mild 3D, great sport, pattern and IMAC type flying get the Extra

BTW...Both planes are configured by the book with no changes in the recommended CG settings and control throws