I like to use them just to see how different hands match up. For me, it is more of a tool to learn the odds better. I never use them while actually playing.
DM should have the answer to that. I have seen a few, but I can't remember where. They all work about the same. I have a pretty fair idea of all hands I consider a "coin flip", which for me is everything from about 45% and up. These are basically pre-flop hands I am willing to go all-in with and how big of a dog I would be in a worst case scenario. Once the flop hits, I just use str8 pot odds calcs, along with my knowledge of my opponents and theeir betting patterns.
Well, I don't know if it's necessarily going with my gut, but if I have someone easily covered, sometimes I am willing to take the bottom half of the coin flip. Conversely, if I am shortstacked and feel this may be my best opportunity (cold cards for a while and blinds about to hit again, for example), then I'll gamble.
Mostly, it's situational. What kind of draw do I have? Did the person limp or min raise? Do I sense weakness? Do I think a large raise can move them off their hand? Etc., etc.
The one I used, back when I used to because I rarely do anymore is the one at cardplayer. Nowadays I try to just go to the next hand and forget it, knowing that I was a 93% favorite at the turn when we got allin just makes me sicker.
