I own 3 CZ 527s in .223, 7.62x39 and .300 AAC, so I'd have to admit to being smitten:
The 527 bolt root positions the handle a bit high, so you may need slightly taller rings depending on the diameter of your chosen scope's eyepiece.
Spare mags are a tad pricey and spares sometimes prove a little fiddly at first. You can only load the magazine when it is removed from the action, so if you run dry without a spare you'll have to single load.
CZ offers a 3-shot flush-ish fitting mag for the .223, as you can see on the lowest photo; it requires a compatible triggerguard -- the older model triggerguard has a web at the back of the magwell that interfers with the shorty magazine. I went with a NECG aperture sight and front blade to keep my fullstock rifle more sleek. I only wish they offered a butterknife replacement bolt handle to complete the Mannlicher-Schoenauer carbine look.
The action is smooth, but you may experience bolt bind when working the knob -- it runs smoother if you choke up a bit on the handle.
The action offers controlled feed, a large Mauser claw extractor, a very cool tooless bolt disassembly method, and good customer support for parts from CZ USA. Stock wood is often a cut above other makes, though I don't care for their 527 synthetic stock design (hence the chassis on my .300 Blackout -- since this photo I've changed the buttstock and grip a couple times).
BTW, $650 is a decent price if the rifle is in good shape. New 527s run around $800-900 around here, depending on model.