Originally Posted by
TehLlama
If it's a pure range use, the 'inferior' 1:9 twist massively overgassed barrels can be a better deal, just because they'll run cheap ammunition more happily, but cheap ammunition is yet another false economy a lot of the time anyway. The M&P Sport comes to mind because it's the cheapest rifle that is more than good enough for range stuff, a lot of in between brands get by on dealer networks and the assumption that because the MSRP is positioned where it is, so too must the quality.
$700 is the low end of the 'not sure if value is a worthwhile proposition' range - like ASH said, once you've cleared $800, it's silly not to just price shop and get a 6920. The $600-700 range, you're about a case of cheap ammunition away in price, so the difference comes down to if you think you'll ever look at upgrading anything on it. The M&P Sport in terms of price differential would still get you a couple magazines and a good sling (MOE PMags, VCAS Sling), which are honestly the most valuable things you can get right away anyhow.
The $600 rifles can withstand some money in parts and upgrades that make sense (MOE Line stuff - magazines, handguards, grips, stocks), but as soon as you're back to peeking above the $1000 mark, you'll be immediately haunted by the fact that a Colt or other top end option is in the same price range. 6920's can quickly become top end units with fairly cheap modifications (Centurion C4 FSP handguard, Aimpoint H-1, VCAS Sling, Surefire X300), each of which can come later, but the final product can be a serious fighting tool that still is great fun at the range.
I'd decide based on how much you want to use it, and how much if any money you think you'll put further into the rifle.