I have the G&G L85. No real problems. I've disabled blow back feature as it can ruin the piston. I'm currently trying to sort the semi auto lock up issue which seems to be a problem on all l85s, although it's not a huge issue for me. The gun has a split gear box and is incredibly easy to open and work on even for me. It has a really nice range and accuracy and I haven't even done any real modifications yet.