The G36 is pretty nice, I've had one since Evike got their second batch from WE back when they first came out. I rather like it, although I'm considering selling mine because I've recently gotten my WA M4 working, and although I wasnt much a fan of the AR series, I've grown to like it. The only issue I've seen with the G36 is the magazines; there's a little plastic tab with a screw through it to hold the metal innards in place. If you just hold the shell while filling the mag with gas, this can fail and drop the mag out of the shell. This is easy to correct, by just holding the mag by the top instead of the sides. Doesn't ruin the mag if it breaks, its just nice to have in place lol. Everything else is rock solid.
And with gas guns in general, it is usually easier to keep it SA only, just because of both the cool down of the mag, and the fact that you only have 30-50 rounds per mag, so it is best to pick your shots and make every one count!