Mine came with a metal guide rod/spring assembly, but I replaced it with this:
https://ssguiderods.com/shop/cz-p10-c/The original made an obnoxious screeching sound as the spring moved down the guide rod. The new one does a little bit, but nowhere near as bad, and with some gun grease on it, the sound basically disappears.
The original's spring was very tight and brass kept coming straight back and hitting me in the forehead. The new one doesn't do that.
I would not personally use a polymer guide rod at all. I've seen pictures of someone's who had their's shatter and the resulting shards ended up damaging the locking block's mounting into the pistol frame. They ended up having to send the whole thing back to CZ. The same thing has occasionally been seen to happen on some Glocks with the single stage polymer guide rods too.