I'd like to look at a few before I buy...

J&S has whole guns from RRA, that might give you an idea?

Are you looking at RRA's quality?  I have a RRA A4 upper that your more than welcome to observe.  I had Mark at OGA order it in because he was willing to cut me a little bit better deal than what I could get it for from RRA directly as a consumer rather than a dealer.

If you want RRA uppers go to ADCO in the Industry section as they seem to have better delivery times the buying from RRA direct, Pete in NH is another excellent source of RRA stuff, and buy with confidence.  I have two RRA uppers and they are both great shooters, the varmint upper is 1in8.  It loves 75gr Bergers!  The 16in A2 is very accurate with ball, 69gr OTM, and spits out the 75gr OTM.  DPMS makes good stuff !  I have 1in9 varmint upper that shoots just as good as the RRA.  I have shot .750" at 300 with 75gr Amax rounds, okay 4 rounds were in that measurement, and the 5th round opened it up 1.25"  

I'm really happy with my DPMS Varmint 24", but I have a very lonely RRA lower sitting in the safe!  I kind of have it narrowed down to a 16" M4gery config, but I want to look at the differences in mid-length vs. std, and stainless vs. chrome barrels.  I also want to see how the RRA Dominator sight looks, vs a ARMS 40L and a riser (don't have the Eothingy...yet!)

I plan on doing nothing more than wasting a ton of money on ammo with this upper!  I would also like to keep the twist 1:9, as I have found a handload recipe for 62gr Sierras that I'm very pleased with.

I have a RRA Varmint with 1in8 twist as well.  I HAD a 20" RRA A2 upper.  I have owned/do own RRA, DPMS, Bushmaster, and Olympic Arms AR's.  And the RRA IMHO is right up there with the best of them (my personal fav's being Bushy and RRA).

Can't really help you out on the RRA M4 thing.  But I thought I'd put a plug in for RRA.