I sure love my kit built CGM Ultimate. I use a Saito 120 and it works pretty well. Selecting the right power plant can be tricky on this model. If you need strong vertical and do a lot of hot-dog flying, opt for the 120. If you are more a sport oriented flier, I'd stick with a strong 91 or the Saito 100. If I were to build another, I'd use the 100.

If you intend on using it for precision aerobatics or IMAC, you may be frustrated by the control coupling. The rudder couples very strong to a positive roll (rolls in same direction as rudder input) and slight pull to positive pitch. Either can be tuned out with a good radio. I fly mine straight (no mixing) and have a blast. For IMAC, however, I fly a different airplane.

Many kit builders do several standard modifications like dual aileron servos, cabane mounting beef-up, dowled firewall, aluminum landing gear, etc. Even with all that, it builds very fast for a kit.

I think comparing it to the DP is fair. Both airplanes were designed by Dave with the DP being slightly larger and possibly having less height in the top wing mounting. The supposed improvement in flight is probably due to the increased size. The DP will be considerably more expensive to finish considering airplane, engine, and servos.

The CGM is a great airplane. Have fun.