You never played MW2 did you? I went back a couple of nights ago and had a spin with the Spas-12 and M1014 (I think thats the name of it anyway, the last semi-auto one) and it brought home just how crap the R870 is compared to them. I was getting hipfire kills where an ADS'd R870 would yield a hitmarker and untimely death.
I love how none of you shotgun-nerf crowd have a single statistic to back up your claims other than 'Oh I had a good game on Nuketown with it'.