Hero Points (APG) usage, and Antiheroes

I'll be starting both a Serpent's Skull and a Kingmaker campaign in the foreseeable future. I plan to limit player character creation options for these campaigns to official Pathfinder sourcebooks, and I want to use the Hero Point rules from the Advanced Player's Guide to replace my old action point rules (taken from the Eberron Campaign Setting). I'd like to get some feedback as to how players use these points in actual gaming from other GMs that are using the rule already. Do players hoard their points to always be able to escape death by paying two points?

Has anyone made any experience with the "Antihero" option? Is the option to get an additional feat too abusable?

I'd love to hear some feedback.

I use these rules (except the anti-hero part) with some tweaks from Spes Magna Games Rewarding Roleplaying and some of my own. I don't have a problem with hoarding so much as I have a problem with the players forgetting they even have them. So I have 6 players that are sitting on 3 AP's, that once I remind them, they spend them almost immediately on rough challenges or hard saves. In my other game the person that uses them the most is a ex-4E player. He knows when to startegically use them to his/parties best benefit.

I've been using the hero points rules in my Serpent's skull campaign, and so far they seem balanced and fun, although a couple of my players tend to forget they have them. The players do seem to try to hoard a couple of points because of the cheat death option though, although I think this is a viable tactic. I haven't used the Antihero option, but was thinking this might be useful to give to major villains.