I dont know how the wieghts can very so much on a plane like this, its not like one builder uses way more epoxy than another, there really is no need to use any except for hinging unless you use hinge glue. Differences in servos would be minimal and even battery differences wouldnt add up to a whole lot. I have a pilot figure so that can add compared to others final wieght. My plane came in just a tad over 14 lbs. Sure it would be in the 13 range without pilot but seriously to get mine any lighter would be expensive for just a half lb difference. My plane wont even drop into a spin properly it is light enough on the wings so you have to cheat it. My engine choice has plenty of power and is only slightly heavier than an os 1.60fx. In my opinion a Da50 would need tail weight and be rediculously overpowered. I was at the field today and had a few coments on the power and how well it did in slow flight. I am experimenting with moving the cg rearward, when all done I think a heavy tailwheel is going to be placed on the plane or just a bit of lead in the stab tube as it would be harder and add more overall weight to mount the battery farter rearward. I love my plane at 14 lbs, just want to get a little more red on the wing for visibility.