Well, normally when you gun it in on a "coinflip" in a cash game, there's enough money in the pot beforehand that it's massively +EV whichever side of the coinflip you're on.

eg 55:45 or 45:55 when you're calling $100 to win $300 ($100 behind, $100 in the pot) ... I'll take either!

Yeah, I think Rhound pretty much says it all. Against any kind of big stack, I think it's very bad play to get involved in a coinflip in a cash game situation.

Here's the main situation where I don't have a problem with it:

You raise AK to $20 (2/5 game) with a stack of $600, and a $100 stack pushes. The range of hands for a stack like that is pretty variable. You may be up against 88, but there is a very strong possibility that you have a dominating hand (weaker A or even a K). A read helps here, but it's generally pretty unlikely that you're up against AA or KK.

I'll probably even make the same cold call against that stack as a general rule--moreso if I think there's much likelihood of being up against a weaker ace.

To view it more mathematically, let's say their all-in range is: 66-JJ (I think they're actually LESS likely to push on QQ-AA), KQ, or A8 or better. From what I've seen this seems fairly realistic. Your big equity against KQ and the weak aces clearly compensates for your small minus against all of these pairs (I'll just make this claim without calculating it out). I also think there are some intangible advantages (for a tight player) that you can gain from giving action to a short-stack in situations like this.