I'll give you a call. I have a set of 48mm Zokes off a 2014 350 Beta Race I picked up and I've been told a few of them have issues with the bushings causing very high wear on the fork tubes because they do not align properly when the forks flex. Apparently they fixed the issue by machining the inner tube in such a way the bushings slightly rock. I'd hate to trash a brand new set of forks.
One of our local suspension guys told me the ICS spring on the '15's is a 1.4 versus the 1.6 on the '14's making for a bit more plush ride in the really rocky root infested areas. I almost exclusively ride really tough trails since my go fast desire has kind of gone away as I get older (a lot older).
I assume you can easily fix any factory issues.
The '14 Beta Sachs worked fairly well. The Zokes are a bit more harsh everywhere although they certainly don't bottom out as easily.