I bought the Turbo S Velocity, 72", in the Northeast (eastern PA). No regrets so far, but it's still early. Also, mine does measure a true 72" - others have reported 75"??
I ride with 50" 4wheelers (mostly lead by my father-in-law). He too loved all that the Velocity had to offer, but was very concerned about the width. 2 weekends ago he took us down the tightest trails he could find, in an attempt to see if we will have issues later on. Only 3 times did we not fit - 2 of which were a matter of staying to one side rather than the other, so no inconvenience at all, the other was a tight fit mid-turn that was not possible like that, so I had to turn around off to the side and come at it straight on, we fit, but slowed them down just a bit.
We're going out again this weekend for more fun and tight trail testing. I have contacted all of the parks we plan to ride (AOAA, Famous Reading, Lost Trails, HMT, Burning Rock, and several more) as well as reading first hand experience from others with 72" machines. All parks said we will fit everywhere, but may come across an occasional tight squeeze. Those with 72" machines seemed to say the same thing.
Nowhere we ride had gates limiting width, and I have no plan on riding state lands, so I do not think we will have any issues.
And just take everyone's recommendations, including my own, with a grain of salt. I did a lot of research before buying 72", and it seems like everyone narrower than 72" says "no way, hell no, won't fit" (or some variation) and everyone with them says "All clear, all good, send it."
Riding with 50" machines, I think I should find out real quick who is most accurate. 30miles in, no real issues yet. I can report back after I rack up more miles and my father-in-law tries to force us down more tight trails.