I also have one of the aluminum SAR's, I have about 3000 rounds thru it, never had it so much as burp. The barrel and receiver are still tight etc. For what I paid at the time, (way before I knew about Jason at IGF or JDL were around), it was a good deal. I know that the guy who has a friend who changes out the snacks in vending machines in the plant at SA heard this or that or whatever. But SA no longer has parts, so they will swap them out for M1A's. It was limited run at a time when SA still did a lot of imports for firearm accessories and parts.
All that said, unless someone has a smokin deal on one, I would pass and go JDL, that will be my next HK. No matter how you cut it the steel receivers are better according to the experts like Jason. With a JDL going for 800.00 I would go that route, I think you will be better served in the long run.