Would you play worse or pretty much the same, if for some reason, you changed the normal pace of your play? (This is disregarding your opponent's pace...for instance if you were playing the ghost)
1.) For players who are a bit methodical and for some reason had to speed up a bit.
2.) For players who are fairly quick and for some reason decided to slow down a bit.
I think there is an optimal pace/rhythm for every player. It pays to experiment, what your optimal pace is. If you deviate from your optimal pace, your game worsens. (Best approach is probably to find optimal speed for different shots of different difficulties. If it's a hanger, treat it like one, if it's a tough shot, take your time.)
I am a slow player but I play faster (than optimal for me) in most matches because I don't want to unnerve my opponents. So I train to play faster to look better even if it worsens my performance. If later I go back to my slower pace, this slower pace tends to be faster than when I started out.
Like in speed reading training: you leave your comfort zone and read faster, when you used to. When you go back to your feel good reading speed, you notice, you became faster. (Hope I was able to get my point across.)
But only reason for experimenting and speeding up my game: I hate watching slow players (Souquet, Harriman) and love watching fast players (Jayson, Schmidt). That's why I don't want to be (or stay) a slow player myself.