Base, prep, and finish will make more of a difference than 500 psi in the concrete. Make sure the contractor does quality work!
The contractor who did my driveway had a stellar reputation, and they and the earthmoving sub they used were great. They made sure to compact the base amazingly well - and everyone involved commented that without it the rest of the work would be junk. 10 years later, not a single crack in the driveway, even on the fill sections.
Here, 3500 psi or 4000 psi concrete is typical for driveways. This will vary across the country dependent on source materials and climate, so the lower numbers would be odd here, but perhaps they are normal there...