I'm a big fan of CZ pistols and have owned ten or so over the years. I still have my trusty CZ 75, plus a sweet CZ 75 Phantom and a CZ 83.

Today I caved to the hype and bought a P10-C.

Out of the box, the trigger was gritty but clean on break. I took it to the range and after about 200 rounds, the trigger smoothed out nicely. The gun shot perfectly with no issues, was accurate, easy to control, etc.

However, the magazine release was awfully hard to actuate. It almost always required two hands. I'd push the release in and it seems like it would have to break past something that it was hanging up on. It did get better over time, but never loosened up to the point that I could drop a mag with one hand without using my support hand to grasp the pistol. Anyone else have this issue?

Mine was stiff, as well as the slide release, when new but after ~800 rds the mag release is normal now and the slide release is getting better.  

It seems that the P-10s need a gradual break-in.

My .02

Download your mag by one round and see if that helps.
It's usually an issue if the mag is full.

Slide release is no problem.

I've read that leaving the mags fully loaded for a week or two helps. I'll give that a try and report back.

The mag release is stiff to push on a loaded mag with the slide forward.  The tension of the slide on the rounds pushing down puts pressure on the mag catch in the mag well.  Even after the mag springs set the slide will still be pushing down on the loaded magazine.  With no rounds in the mag and just the follower contacting the closed slide, the mag release is stiff.  CZ never has said it but I think it is designed so you don't bump the ambi mag buttons and drop a loaded mag.  If you notice the FNS is the only other handgun with fulltime ambi push botton mag releases.  All others have the ambi mag button on one side or the other.  HK and Walther have the paddles that you wouldn't bump carrying in a holster.  With the slide to the rear and the magazine empty the mag button pushes easily and the mags fly out like they should.  David

This won't work, it has nothing to do with the mags being tight.  It's the design of the release itself.  If you take a look, it actuates a lever forward, then the mag drops.  You're working AGAINST the mag spring to depress the mag.  Kind of a stupid design, overly complicated IMO.  Mine was exactly like this, insanely hard to depress mag release (only worked with slide locked back, or only a few rounds in mag) and the mags didn't drop free.  The gun ended up going back to CZ where they replaced the out-of-spec release.  It still requires some force on a full mag, but it's doable, and the mags drop free.  Good luck.

Update: Left the mags fully loaded for a couple of weeks and dropped the mags repeatedly and things have loosened up considerably. There's still a bit of a "catch" before release, but that has more to do with the design than anything. Can drop a fully loaded mag with the slide closed with just my thumb...take a bit of pressure, but a empty mag with slide back (most common) is a piece of cake.

ECZellent!

mag and slide release loosen up after shooting for a while.  Mor reason to go shoot!

Common problem, but cycling and usage will make it sing after some break-in.