I have one. I built her from a kit 4 years ago and she flys just about as nice as a trainer. I am using a TT .91 4st in mine. She doesn't have an over abundance of power but flys very scale like and sounds great. So a 120 4st should work great. I am using Hitec 425BBs; all around. No trouble whatsoever.

I ditched the wire landing gear after the first few flights as I found them to soft. I made a set out of Great Planes 90 size Dural aluminum gear. I trimmed about 1/3 off and fit them to the bipe. No more gear bending problems.

I also tossed the N struts and made my own quick release struts. I used spruce pushrods with Robart pinned hinges sunk into blocks glued into the wings.Then I used Sullivan quick release ball links to attach the bottm wing to the top.

I have attached a few pics of mine. It initially started off with a GMS.76 2 st but got swapped out with the TT .91 4st for sound and scale realism.

Enjoy
Curt