Looking to purchase a 91 Ski Nautique

Great wakes, but from what I've heard the MC PS 190 of the same era had amazing wakes and is a great hull. It's a toss up. The MC is all fiberglass and the SN of that year still has wood. You can't go wrong with either model. For a boat that old I'd leave it up to condition of the boat.

The '91 Nautique and '93 PS190 are both good boats. My dad had a '92 SN, and a friend of ours has a '94 PS190 (LT1,1:1). Quick comparison:

Barefooting:
Top end on the Nautique should be at least as good as the MC, even with the 240 horse. Our '92 with the GT40 heads was ~2 MPH faster than the PS190, even with the LT1. The barefoot wake on the MC is better, though- the rutt in the center of the wakes on the 90-96 SN hull is the worst Ive ever experienced. Otherwise, its fine.

Slalom:
Boats are very comparable. The PS190 probably has a slightly smaller wake, but the SN is very good as well. Both have a rooster tail at 22 off, the SN's is probably slightly larger. The spray is much better (nonexistant) on the Nautique. Both boats track well, I'd say the Nautique may have a slight advantage in the course.

I agree with BKH as far as driving position goes- nothing beats the functionality and ergonomics of a Nautique. Both boats are built very well. Price on either would depend largely on condition.