It definitely depends on the circumstances. Viaweb sold to Yahoo for stock before it went up in a huge way. They probably would have had a much lower price if it was straight cash.
In one of the Startup School talks, someone said the $50 mil in Yahoo stock turned into $750 mil. So getting stock worked out pretty well for Viawebbers.
there's a huge difference between public company stock and private company stock. public company stock isn't necessarily bad: you can decide to do what you want with it, since it's fairly liquid. if you hold on to it and the price drops, that's a risk you assumed.
private company stock, however, is completely illiquid, and has a very high probability of being worth $0, and that is usually what people mean when they talk about accepting stock vs cash. agreeing to a stock buyout of your company by another private company can be good, but you're essentially trading your risk for theirs.
