ive flown 2 ultimates for almost the past 10 years.

powered both with supertigre .90 with a jtec side muffler. wieght is 8.5lbs. i can take off, then pull vertical right after and go maybe 300ft up (give or take..) and hang on prop until i over control it. still naturally nose heavy, just havent gotten around to putting wieght in back... too much fun!

for a plane in its category, the ultimate is a very good dead stick. not a trainer by no means, but not a brick either. depends on the wieght/wing loading naturally.

i ve even flown a 60in convert witha gas engine. it was nose heavy at the time, but not too bad..

guess im just used to my 'baby' flight characteristics...

as for the original question, use the 120, should be fine. not like a YS, but im sure it will do everything u want it to do.