I own a Sig 556. And I've owned an ak47 (and liked it). The Sig is hands down the best weapon. I've probably shot 20k rounds through it without a hitch. It's smoother, easier to aim, more accurate and built tough. It will put any of the 5.56/223 variants out there to shame and I would certainly take it over the AK. I cant say for sure about the R version but i imagine it is no different than the regular. The 556 is my long gun of choice for when im on duty, because I want something that is unfailing.
Had a SIG 556 and yes it is a good weapon, but it has a lot of limitations. Mine was awesome and had all Swiss internals and Swiss made gas-block. The newer US made 556s pale in comparison to the older ones. The other problem with 556s that I wrestled with is what if something broke on it. Back-up parts are hard to find and crazy expensive(i.e. bolt, gas block, bolt carrier). My 556 was no more reliable then my Noveske, LMT, Spikes, Colt or Stag ARs.
I keep an 454 casul Alaskan and an hk p7 next to my bed for home protection.
454 casul...good lord man, is that incase a rhinoceros gets inside the house?
I was just looking as a cheaper ammo rifle to shoot. I also want to get into 1 caliber of ammo. I sold all my ar's but a 308 I have and I now have 2500rds of 223 brass I end up shooting in my bolt action rifles. For all you ak guys how well does the rail attachments hold zero on the ak's side mount?
454 is many for when I go hunting up north (bear mostly but drops boar pretty easy). And I'm selling. Any suggestions on what's the best ak to buy.