1) The P-01 is a compact version of the full-size gun.
2) Standard hi-caps hold only 13 or 14 rounds (depending on the follower design), as opposed to the 15/16 of the full-size version. The grip is shorter. Full-size mags will work in the gun, but will stick out. Many folks carry a 16-round standard mag on their belt, and a factory 13/14 round mag in the gun.
3) The P-01 has a decocker. It cannot be carried "cocked and locked"; the standard 75B can. (There is a decocker version of the standard CZ, too, called the 75BD.) The P-01 and other decocker versions are carried on the half-cock notch, the place to which it is decocked. All "B" series CZs have a firing pin block, so decocking to the half-cock notch is not a safety issue.
4) The P-01 has an alloy frame; its noticeably lighter than the standard steel frame.
5) The P-01 has an accessory rail, to accomodate tactical lights and similar attachments. It is wider at that end than the standard compact CZ (PCR, or 75 Compact), and will not fit a typical CZ holster.
6) The P-01 has a recurved trigger, which shortens the trigger reach for those with shorter fingers or smaller hands. Not a big deal, but noticeable.
7) There may be slight differences in the sights, but the top ends are othewise the same as the other "compact" CZ; the slide will work on any other 75B-based gun.
8) The P-01 has undergone a rigorous NATO testing regimine. Its a very robust gun. The 75B didn't go that route, but with a steel frame, its probably not necessary.
9) The P-01 has a full-length guide rod. Many P-01 owners convert the plastic guide rod (which works perfectly) to a steel one, because they think it looks better or functions better. There's no question that it looks better.
(There may be other differences... but that's all I can think of, at the moment.)