88 vs. 90 or even 88-92 is neglible at best the real difference is going to be overall dims, longitudinal & lateral flex, "metal" type of wood and other factors like base material. don't get so caught up on the width, it's just one factor. The 88 is a clear notch up on performance. Phil said it best, it skis narrower when on hard pack and skis wider when on soft snow. It's uber stable at speed, holds an edge on steeper chalky stuff (I didn't ski anything steeper than 30 degrees, which isn't that steep) but the tops of some of the cornices and drops were pretty steep but short. The Pilgrim is a greaat ski, just more soft snow oriented, it does have a speed limit, where as the 88 didn't (I am not darren Ralves). in manky sofish refreeze, suncupped crap, it was so stable, A strong downhill leg and the ski just ripped through it all. Again, I was blown away at the stability in this stuff.
So to summarize, the pilgrim is a great soft snow ski, very capable in some powder, loose soft snow, soft groomers and very nice in bumps. (No bumps to try the 88's in) A very easy ski, forgiving and fun, lots of energy. The 88 is a more serious crud busting, soft snow, hard snow ski, more powerful and stable.