Thanks for the answers KY1911 and EkuJustice. Appreciated!
If the DI gas system works so well, as it has since the early '60's, why on earth did they start using the piston on the AR's? It seems to be a European thing though. The Anderson I looked at impresses me more than the Smith. But before any one want to tar and feather me, the M&P 15 is one of the most popular AR here in SA, followed very closely by the Norinco CQA. The Norincos are cheaper and easier to get. The Anderson seems to be a more solid firearm than the Smith.
Ar's are still fairly mistrusted here, being made out of aluminium. Most shooters here go for the LM 4 rifle, which is a semi-auto version of our military rifle, the R4. It is a copy of the Isreali Galil, which as everyone knows is a copy of the AK. I used the R4 in service rifle shooting sometime back, and it is heavy and not as accurate as the AR I tried for the first time a month ago (an old early 1980's AR-15 with the Veitnam era triangular hand guard). That rifle was way more accurate than the LM4/ R4 platform and the recoil was less (due to reduced mass of the moving parts I guess...)
I like the AR and I am leaning towards the Anderson as I like the round, free-floating aluminium for-end. I would just like to get more info on it. I have tried looking at their website.
TIA