Is there any significant gain of the bell super 3r mips over the 2r mips? I am looking into buying a full face helmet with a removable chin bar, both the bell super 2r mips and bell super 3r mips seem to a good choice. The super 2r is about 90 pounds cheaper than the 3r and i would like to know if there is any big reason to get the 3r over the 2r.

Thanks.
I would imagine the 3R is just more refined. We don't do product recommendations so to speak but comparing the two on the Bell website should suffice in helping you determine if it is worth the extra money for what you will be using it for. 

The website lists the major difference as:


  For the new Super 3R, we’ve added the new Float Fit system and dramatically improved the fit and comfort by revising the shape both inside and out


In addition i would compare the product specs and see which is better for you, your wallet and your intended application.

2R -


Breakaway Screws
Fusion In-Mold Polycarbonate Shell
Goggleguide™ Adjustable Visor System
Integrated Breakaway Camera Mount
MIPS-Equipped
Overbrow Ventilation™
TAG™ Fit System
Wraparound Protection™
X-Static® Padding


WEIGHT: 694 Grams 
VENTS: 23 helmet, 4 brow ports, 6 chin-bar

3R - 


Breakaway Screws
Float Fit™
Fusion In-Mold Polycarbonate Shell
Goggleguide™ Adjustable Visor System
Integrated Breakaway Camera Mount
MIPS-Equipped
Overbrow Ventilation™
Wraparound Protection™
X-Static® Padding


WEIGHT: 784.1 Grams 
VENTS: 23 helmet, 4 brow ports, 6 chin-bar vents

Seems to me the major difference is the 3R uses an improved fit system while also weighing nearly 100 grams more. Other than this my guess is the price difference is simply because the 3R is the newer aka latest and greatest.

Also i would recommend trying them both on if at all possible, when it comes to full face helmets a large of one brand is totally different then the large of another and the fit and comfort can very greatly. 

My personal opinion would be to go with one with permanently attached chin bar, but that's just me. If i'm depending on something to guard my mouth, i would rather it not easily detach and reattach. I ride the tamer trails around me with it as well now that i am used to it, it really doesn't bother me. I do get some odd looks every now and then though. 

Hope this helps