I've run the following 30's (in order):
1) M1A: Newer "Standard" version. Shot well, typical good 2-stage trigger, but the build quality sucked. The new ones are a shadow of the older ones. Poor fitted stock, parts came loose, etc. One of the hammer hooks sheared off one day. It was a brittle MIM part from some South American country. Had the other one come off as well, the thing would've gone full auto. SA refused to replace MIM parts with either GI or aftermarket. Ended up telling them to pack sand up their 'lifetime warranty' on a substandard piece of equipment and got my money back. It was a little bulky for me and had the worst recoil of everything I'd shot.
2) Rock River LAR-8 (AR-10): Nice rig (MOA shooter), but it was a jam-o-matic. Could not get any more than 5 rounds through that thing without having to whak the charging handle or buttstock a bunch to get the case out of the chamber. On top of that, RRA claimed it could use the cheap FAL mags. It was BS (still doesn't from what I understand) and then they gave additional BS about having both the platform and the mags in consistant production. The mags never materialized in over a year and they could never fix my jamming issue even after 2 recalls to them. Too bad. It was super lightweight and shot well when it ran. Loved the RRA 2 stage trigger so much that it's what I have on my AR15 now.
3) DSA FAL: Currently my 30 cal. Purchased it as it was my last real option plus I had a few of the mags that I bought for the LAR-8. It has shot everything at about 1.5-2 MOA, though I've managed a hot hand load to touch 0.75-1.0 MOA. Zero problems. In fact, I had some russian TULA ammo blow up in the chamber (case head seaparation). This resulted in a blown out mag and the removal of a bunch of hair from my right hand. Otherwise, it took me about 2 weeks to get the case out of the chamber. After that, gave it a scrubbing, checked the chamber and headspace, and it's still shooting the same. Needless to say, I'm sticking with the FAL. I'm pretty sure it'd shoot and with dog turds in a case. Easy to clean, cool to run (piston), but it is kinda heavy. Out of the box, the triggers are quite heavy (12 lbs or so) and the sights are rudimentary at best. Don't expect match accuracy out of this true battle rifle, though mine is pretty good. It's also not the easiest to get optics on, but that is becoming less of an issue. I've also noted that they're getting harder to find and more expensive. Glad I've got mine!
That being said, I've not shot a 'real' AR10. I've never had an Armalite, DPS, or any other known manufacturer. The BIG advantage of an AR10 is that it feels like a big AR15, runs like an AR15, and it's significantly lighter than most other 30-cal platforms. But my FAL has never taken a dump that wasn't caused directly by either me (ex. not seating a mag) or by a crappy surplus magazine. They just work. I wouldn't mind trying another AR10 (ex. Armalite or Windham Weaponry), but right now my safe is full enough with 30-cal rifles!
Speaking of which: range trip tomorrow with the M1 Garand. Did some work on it and have to reinstall the front sight. This means I have to re-zero it. Oh well; I suppose I'm forced to go to the range again.