RE: Great planes ultimate 160
That's good to hear. I just got done adding 2-1/2" glass tape top & bottom on the lower wing and sandwiched fiberglass batten stock into the supplied joiner blocks before epoxying them in and the wings together with West System epoxy& 205 slow hardner thickened with chopped glass flocking (think of it as four hour epoxy - for better or worse). Added maybe two ounces of weight but (I hope) strengthened the wing roots considerably above stock & instruction manual. I also pinned the cowl blocks into the front fuselage former with 1/8" bamboo instead of relying on just epoxy.
Otherwise the model seems to be rugged and complete out of the box. All I've added so far is a pilot. I'm using all stock hardware. My only complaint is some twist and wringles/bubbles in the covering that defy smoothing. I'm pretty sure I melted and re-formed the foam turtledeck near the vertical stab under the covering with my heat gun and iron!