Anyhow I'd be interested in other opinions on the revised linked braking on the 15+ vs the 14 and older. I'm still on an 08 and thinking about going to a newer one mostly for the improved heat management. Wondering if it's worth the extra $$ for the 2015 and up bike.
Most of the extra $$ for the gen2.1 vs gen2 will just be because it is a newer model year. Even if you are comparing two new ones (unsold old new bikes vs. current year). I expect it will be impossible to find a new gen 2 (2010-2014) at this point, since those are now at least 7 years old (by model year) and dealers would have become pretty desperate to unload them long ago. Not sure though, since I hadn't shopped. So really, it sounds like you are talking used. At that point, the warranty has been ticking, and that does (to a lot of people) matter quite a bit. Plus you then have to worry about condition, modifications someone did, how it was maintained or treated, etc. Gets complicated pretty quickly.
The only meaning diff between < 2015 and 2015+ is the reduced linking. If that might matter to you, then you have to figure out how much it matters. I expect for most people, it won't matter at all, especially compared to price, color, condition, warranty status, and availability.
As for the ACTUAL difference in linking- we have no real technical data (quantitative), just a marketing blurb. So any information you do get will just be subjective "impressions". In which case you have to factor in placebo effects, who is comparing, bias, exactly what they are observing or comparing to, and if there are other confounds- like how old a bike they were using, did they test both modes, were "test" conditions identical, was anything physically wrong with the comparison bike, etc. And you won't find a double-blind test, for sure (not even a single-blind test).
