I have, once, and was not a fan. The issue with this kind of thing, and with inspiration in 5e, is that it requires a special kind of GM to make it work. While I might only have a single direct experience to work on, I do have plenty of experience with human nature in general, and that's the problem. It's far too easy for a GM to play bias with these rules, even if it's only subconscious.
"I, the mighty Barbarian, rush past all the kobalds, shrugging off their spear jabs in my rage as I aim for my target, the dragon leading them all. I leap, great axe gripped in both hands and swing down, cutting deep into his neck!"
GM1: That was amazing, +1 for RP!
GM2: Kinda over kill don't you think? -1 for over the top.
GM3: Nice, just what I expect. No bonus.
What is 'good enough' for a +1 bonus? When is it too much? Granted part of these issues easily work themselves out when you know your GM. But if you don't, it can easily feel like one player is getting all the favoritism and you're being ignored. Plus there's the style issue. What if your style doesn't jive with him? You could do amazing things, and never be rewarded for it.
The latter is what happened with me. Because my GM didn't like my style, I never saw a reward, no matter how much work I put into my RP. Another player though, got a +1 bonus almost every attack. It got to the point that I was just expecting him to have that bonus and took it into account any time we were planning our attacks out.