If you have the money, go for it. I just took one on my last break in run yesterday. It's pulling into the powerband solid now. The amazing thing I noticed was how usable the power is. Sometimes I forget I'm in 2nd instead of first when coasting almost to a stop and then getting on the gas. When riding on wet pavement I use to hit he gas and when the powerband hit it'd break the tires super easy. I was on a wet street the other day, hit the gas and the pull started so soon it gripped and pulled the front end up... amazing. I have 28mm (trail mx riding) fattys, v-force and grand river racing ported the cylinders for the stroker crank.
Keep in mind, you'll never be the fastest. If you need a crank or want to spend some money that's a good way to go. You'll need more than a crank though.
Head (new or modified)
porting
crank
It's not cheap, plus all the other things you wanted to do... topend... etc...
It is a gain in performance for sure though.