Well with over 28 hours flight time on my Eflite Ultimate, 2 crashes and 1 inverted landing okay another crash the weak spots I found were the bottom wing mount, the motor mount carbon rod and the CA glue joints. I have added 2 3" balsa 3/16"x1/2" triangle stock under the bottom wing, used epoxy on each of the wing glue joints since the real issue I had was the CA was simply not holding well enough and I injected CA around the first 5” of the motor mount carbon rod. Using epoxy on the wing glue joints has produced a much stiffer aircraft and added an unnoticble difference in weight when it comes to flying, but it did make the plane more predictable in flight, I think due to less flexing. Mine weighs 14.4oz with a HiMax 2812-0650, CC10 ESC, JR610UL Rx, 4 GWS servos and a TP 1320mah 3S1P li-po and it flies great. 11oz even without the battery. I only fly outside so a bit heavier is okay with me.

Oh yeah I did have 1 other problem recently. 1 of the aileron servos came loose in flight producing a very hard airplane to fly, happened during a harrier about 12” off the deck. The servo was mounted with the double sided tape and the tape held fine. However, the covering on the depron had come loose from the foam and the servo was moving all around with any input.

With nearly 30 hours of flight time on this little foamy I think it’s almost time to retire it. I wanted a 3DFOAMY Advantage bipe, but they have now gotten too big for my motor/ESC so I will probably get a bipe from Fancy Foam.
BTW, I get 20+ minute flights with my setup, about 15 of that being 3D flying.