I started using hero points like benes in savage worlds. A white one spent before the roll gives you a +8 on 1d20 and +4 if spent after the roll. Two white ones spent will recall up to a single third level spell. A blue chip lets you reroll any die and also can be used to recall up to 5th level spells. A red chip lets you reroll any die or sets of dice (damage for instance), make me reroll anything (I started rolling in front of the players), nominate a player for a bene (any level lower than this one) or make a fate roll. Fate roll is specifically for Al Qadim and involves the plot cards and percentage dice roll compared to the character's current favor with the genie. So far I have ran the benes in all games including the final with errtu and they have all worked very well. The players can also take hero point feats but those feats only apply to the white 'hero points'.
They keep the best roll on all rerolls not just the last one rolled. They can never use any bene to 'stave off death' which is contrary to the Hero Point rules in the RAW but I care not. I have seen that used and abused too many times.
I am also thinking of letting them spend a blue one to get a health roll (second wind kinda) where they roll their HD and recover that many hits with only Con bonuses (not penalties) applying.