changing hopup rubbers is pretty trivial. I believe g&G soc16 has springfield trades as well.. if not at least stamped trades.
The weak point on both CA and G&G m14s is the stock though, they have issues cracking at the grip or at the magwell. They need to be reinforced and filled with epoxy inside to help keep it from breaking. The rest of the gun when it's together feels really solid.
BTW, Daedalus of scout the doggie fame sold his RAtech EBR months and months ago. Scotland was too cold for it to work properly. I don't know why people still think he has it, it's been gone since at least last summer.
I futz with V2s, V3s and V6s. I could be wrong... but probably, most likely not, as far as I know.