Lots of changes. The fit is updated, gen 2 features Boa 360, polartec lining, no replaceable brim, and MIPS. More on reddit.com

Helmet fit is highly personal. What feels great on your head might be uncomfortably narrow for me. Or whatever. So I'd take those fit complaints with a heavy grain of salt. Aside from that, the big difference is going to be weight. Like you noticed. Smith uses a material called Koroyd, which basically looks like a honeycomb, to make their helmets super light well ventilated while still providing top-tier protection. The weight makes a slight difference, a lighter helmet is simply less on your head and that's obviously more comfortable. But I wouldn't say the Mod5 is heavy either. If you want low weight, have you considered a less ... complicated helmet? Something like the Smith Code gives you the same Koroyd construction, just without the adjustable vents or hardshell construction. And it's a lot lighter. I have one personally and I'm quite happy with it. Or there's the Oakley Mod1, which I'm less familar with. Or any of the dozens of other helmets out there. They all pass the same safety certification, so it's not like you're getting better protection by spending twice as much. More on reddit.com

Yes. MIPS is worth it and something I’d always be looking for in a helmet. You shouldn’t skimp on something that protects your head/skull/brain. More on reddit.com

Got my Medium - this has a tighter fit compared to Bell and Bontrager Almost feels like it's suited for someone who's a conehead Pros: so stylish. Prettiest helmet Ive had Cons: venting. It's horrible, maybe in line with the old Giro Air Attack. I had the Bontrager Ballista before and that had a feeling of the air travelling through fhe the helmet, but this one the air enters at the front and it's just there. No air flowing through fhe the back That being said this might be a good helmet for Spring or Fall, but I think Ill be keeping my Bell Z20 for the hot days. I dont have a wind tunnel at home to verify their aero claims (i dont think Oakley posted any numbers anyway?), but I did break some PRs yesterday probably because of my better position on the bike that I recently got done More on reddit.com