As a current XFP95and former KPS 88 user here are my thoughts on the comparison:
Note:
I have barely hit with the XFP95 stock. I went in knowing I was used to heavier swingweight racquets. I leaded-up the hoop at first and was astonished at how the ball catapulted off the racquet; I found I had little control over put-away balls. I eventually took off all the lead and placed silicone in the inside of the pallet (it seems as though it was made for this sort of customization, having grooves sized perfectly for silicone or 1/4" lead tape). Anyone who has hit with a customized version of this stick agrees that it plays better with a bit a weight. Mine weigh 350 grams and are 8 Pts Headlight.
KPS88:
If you can get the weight moving this hits the bigger ball in terms of weight and pace. That being said, I don't know if this necessarily describes you. I ran across people who played pretty well with this stick at the 3.0/3.5 level, who wouldn't be able to use it at a higher level. No knock on them, they had solid mechanics, but were they not moving the racquet with a fast and long swing, more like a medium and medium swing, and they could line the ball up because it wasn't being hit sharply away from them. That being said, at the 4.5 and up level playing with the KPS88 is difficult becuase of the defensive situations in which you will find yourself. If you have good strokes and eye-hand coordination, this is the put away stick. The only thing you need to keep in mind if you do have those things, is that this brand of tennis is not as easy to pull off day in and day out.
XFP95:
It more forgiving, and any shortcomings this stick has in terms of power can be made up with customization. Some people who are used to more forgiving sticks than a 95s might have problems here, but my personal opinion is that they will adapt and their game will improve as a result. Because of the lower swingweight and larger head it is much easier to spin the ball than the KPS88; it is also harder to flatten out and put away the ball. I does not volley as well, this had to do with stability...it is still a stable stick, just not as stiff.
You long term gameplan might look something like this KPS88 to develop strokes >transition> Larger more forgiving racquet to further develop game >transition> back to the KPS88 now that you are able to mave very well and strike very well.