I'm happy with that trade. Glad that your are also.I had one for awhile and had no problems wit it, it shot great and was reliable as could be. I just traded it for another gun I wanted worse, since I am heavily vested in the AR platform for the 223 cartridge, parts compatibility palyed a role in this decision.
Plus the trade was for a 308 gun that I'd been looking at for awhile, I needed a good 308 semi that would reach out there so traded the Sig for it.
I'll stick with AR's but would not hesitate to recommend the 556 as a go to gun if your not vested in the AR platform yet.