Well, based on everyones comments, I just got home from APD with 2 new MP5's, an A4 for me and an SD5 for my son. As much as I like my Echo 1 M4, the build quality is immediately noticeable. Haven't shot it yet, batteries are still charging, but can't wait to come out Friday night and give it a run. Might have to wait until next week though, gotta get extra mags and they didn't have the bulk boxes of mags in stock.
Thanks to everyone for your suggestions.
phxflyboy