I have a 2002 Yamaha Grizzly 660. Carbed model with no EPS.
It works well. I liked the Grizzly lineup because as someone else mentioned above, the 4 wheel is in when it’s in. No pressure sensors to tell it to engage and disengage when the machine determines necessary. You control it. Also has a front differential lock so you can lock in all 4 wheels and keep them locked in if needed.
Sometimes the steering can be a bit heavier with diff lock engaged but it’s not bad. I don’t see the requirement for EPS though I suppose it’s a nice creature confort on the machines that have it.
Mine had low hours and i snapped it up with cash several years back. Been a great unit with no real problems. Only comment is the 660s are notorious for being cold blooded and I agree that mine is, so I can see the benefit to having a newer fuel injected machine.