Like many, I bought a Super 2R MIPS helmet because I wanted the option of running a chin bar for more gravity oriented riding. My head shape is oval-ish and I fall on the bigger side of Bell's Medium sizing. Because of the well known pressure pointshot spots with the Super 2R in Medium, I had to replace it with a Large, which solved the pressure point problem but was otherwise too big for my head.
Fast forward to the release of the Super 3R, which Bell purportedly designed with an improved fit. On a whim, I bought one from WBW in a Medium. I am happy to report that it fit me perfectly and the helmet in Medium is very comfortable. The Float Fit is a welcome improvement over the old (and clunky) TAG fit system and has been reliable so far. I sold my Large Super 2R on eBay...
The only downsides of this helmet are its relative weight and ventilation. Without the chin bar, the Super3R weighs a good 100g more than a POC Tectal Race (which does not have MIPS). Even though the Super3R has plenty of vents and internal air channels, the MIPS liner effectively blocks the air from flowing over your head.
Overall, I'd say this helmet is an excellent choice for all mountain riding and would recommend it to anyone looking for a single helmet to handle their MTB needs.
This helmet has an adjustable size which helps it fit just right. It's comfortable, well ventilated, and looks great (I went with white) while providing solid protection.
I initially bought a different brand of MIPS helmet which I didn't like and returned. This one fits great and is really nice looking. The MIPS insert will make it feel slightly different than a conventional helmet, but was no issue. Very nice helmet and an added benefit of being even safer.