From everything that ive heard, and then from using a friends g36c and another teammates tavor tar-21.
Those are really the only two ares guns i would use as of yet. I look at it this way, irregardles of what i buy, eventually im replacing the internals anyways, so having quality externals that will last, and wont snap super easy if i do something stupid and trip over my feet only to land on the gun, is pretty high up on the list.
making the replacement internal parts for proprietary parts, more available to consumers would be a great move to start with
and then if the gundocs are noticing the stock internals are really having that many problems in terms of quality, definately upgrade the quality of the stock internals
even if it means raising the base price of the weapons a bit, adding that long term reliability would be huge
kudos to you guys for actually putting yourselves out there on what can sometimes be a volatile set of forums, im sure you will get lots of feedback that should be able to help you guys out in the long run