I made the move to a Cat Z1 non turbo 4 stroke this season. I am a trail rider, I am a big guy, I like to go fast, and the only time I go off trail is to stop for a burger and a beer. I am not a ditch banging, boondocking, hill climbing, fire breathing, clutch tuning rocket pilot.
Why did I buy a 4 stroke? Well, was looking for a comfortable ride (big, roomy), power, longevity of engine. Also nice to get better mileage, no oil cost, and no smell.
My Z1 (so far) appears to satisfy my needs. I can go all day and be comfortable (yes, I know there are 2 strokes that can do that, too). It is powerful, clean running, and fast. It puts a smile on my face easily.
It is heavy, but if weight was an issue I would go on a diet and not blame the sled. I think the worrisome thing about the sled is the complexity. With the old Polaris Indy if it farted you would just pull off the exhaust and fix it. Not with this one! While I am sure my buddy and I will figure it out, it is complex.
For me, the issue was not 4s vs 2s. The sled I liked, the sled that fit, the sled that I kept coming back to was the Z1. It happened to be a 4s and I thought that was a positive for long term, year after year trail riding.