Killed my Spikes conversion today. I think it is a different part than the drop in since it was their dedicated upper system so I still expect better. I have about 1500 rounds through it so shouldn't have been too much wear and tear. The sad part is it was just now starting to function reliably with subsonic ammo :(

Broke the back contact piece off of the firing pin. It started clicking and not going bang, pulled the upper and found the piece rolling around in the lower.

http://i269.photobucket.com/albums/jj62/jpbrad06/Guns/spikesbroken.jpg

Edit: Nope, same part. $17 from Spikes but I'm hoping they warranty it.

That sucks. :(