I can’t speak to the new IsoBow tech, but I had a lower-spec (9.5 as well I think) Procaliber a couple of years ago that I built up with new wheels and other parts ( I had access to the Trek bin back then 
).
Generally speaking, it was a great bike, and the new one looks to be even better.
The geometry is finally updated, and ditching the IsoSpeed was a good idea in my opinion. There’s no headset cable routing (thank god), and the spec isn’t too bad for the price.
It comes with Shimano hubs which is really surprising as that’s normally the cheapest part of bikes at this price point which can cause more issues than most people think. Most of the Formula/no-name hubs really are trash.
If it were me, I’d pick one up and replace the fork (sell the old one before using it), and if you feel the need for a new wheelset that could help too. Also, I always swap to an XT shifter. They feel so much better than the cheaper ones and have better functionality as well. 
I’m sure you’d love it and the purple flip is always fun!
