Crushed concrete is an excellent material for driveways and parking areas. It doesn't dust up very bad like limestone and stays in place very well once it settles.

You should walk over it a few times though to pick up any wire and nails that could puncture a tire.

I am going through this same situation myself.
We have just over 5 acres, with a long curved driveway, that drops down to a separate shop also.
My findings, after having half a dozen estimates from different contractors:
The 5/8" crushed rock interlocks well, but you will have dust (good base, if you decided to go with asphalt later).
Crushed concrete also a good base, interlocks, not as much dust, but some, and some pits crush them too small, making it powder like (non-effective).
Third option was ground up asphalt-great base for actual asphalt later, if you choose, no dust, will actually melt into each other in extreme sun, it's black, and compacts very well.
Ground up asphalt is the option I am going with.