SonicWall TZ300 vs Cisco ISR 921

Good afternoon my fellow Engineers.

I manage about 170 locations that all have SonicWall TZ300's with about 5-10 employees at each location. I recently ran across the Cisco ISR 900 series routers, specifically the 921. It appears they're similar in price, and the 921's may possibly be cheaper. I need to confirm with our Cisco rep. However, before I do all of that, I'm curious if anyone has experience with SonicWall and Cisco SMB gear and if they prefer one over the other and why. I have about 20ish locations that I'm going to be rolling out new gear to so I'm tossing around the idea of trying out the ISR 921's.

Obviously I'm aware that in general, Cisco is better than SonicWall, and all SMB gear is meh, but still looking for opinions.

Thanks