Dragonheart - I'm sure that there are bad kits out there from every manufacturer. I have built kits from many ARF manufacturers and WM is still my favorite choice. WM nitro kits I've had have all been amazing quality and superb flyers.

WM .26 Cub - My avatar... need I say more? Assembly a pain if you have big hands!
WM Rambler 30 - The only plane I've bought two of!
WM Utlimate 30 - Absolute joy to fly (pain to set up)
WM Cap 232 - Great for standard aerobatics
WM Zen 50 - Rock solid construction... F3A pattern ship

On the other hand I didn't like EP all together
WM Rambler EP (First batch) - okay but needed a 1mm shim to get the wing parallel to the horiz. stab.
WM Clipped Wing Cub EP (First batch) - Warped wing

I've given my comments to WM for the EP series and hear that they are making all the required changes.

Other WM kits I've flown but not owned
WM Super Sports 30 - recommended as 2nd plane
WM Super Sports 40 - also recommended as 2nd plane
WM P-51 (40 size) - good sport scale mustang
WM T-34 - great first warbird

All in all, I believe WM do make great ARFs. Maybe the P40, due to its low sales volume, never got the attention it needed to improve. I would suggest you write them and see if you can help them improve it.