safebet,

I can only comment on the Top Flite Contender. I was real easy to build. The kit quality was excellent. The toughest part I would guess would be the cowling. Some sanding & shaping involved to get it to look like the plans. As in most kits the last 20% of the work is the finishing and controls etc. This seems to take as much time as building. But there are no surprises in the construction.

The Super decathalon I will leave to another member to comment on. I am not familiar with it. (yet). Good luck in your decision.

Sledge_78