Did another test. Under "Show Library" I set it to Downloads. I have nothing in that folder. Closed P8 and rebooted. Now it only took 25 seconds to start P8 and 7 seconds like Wimvdb if it had been cached first. So I guess it's my big runtime dir it has a tough time to handle :-(
Free ram is 6.3GB now so P8 will eat 2GB of my free ram to "handle" my big runtime dir while PoserPro doesn't.

I hope bagginsbill can come up with something to fix this. I'm willing to beta test!