I have tried it and thought it was pretty darned good. Maybe it's because I haven't had meat in quite a while, but honestly I totally couldn't tell it wasn't.
For sure these won't get many hard-core meat eaters to go veg, but for those who want to but have a hard time with meat cravings and want some sort of comparable substitute, Impossible and Beyond products seem to be the most promising solution so far. They may not be exactly healthy and I don't think anyone is condoning eating Impossible burgers regularly, but if it takes away from the demand for beef by that much then it is good in so many ways. Since you originally posted this, Impossible and Beyond have gotten wildly more popular, which to me, hopefully, translates to less demand for meat. I have actually always liked the old black bean and some soy 'burgers', but many don't, and I never thought of them as actual meat substitutes that would ever sway anyone who wanted to give up real meat. Impossible and Beyond I think actually can. We had a Beyond Burger night for my girlfriend's parents, and her step-dad who is a definite meat-eater and thought he would hate it, actually liked it and said even he couldn't tell.