Well I had to try it, here is my general opinion:
Expensive $7.02 + Tax. About $8 really. Compared to the $3 whopper, yes it is but compared to most places that sell the impossible burger is about 20-30% cheaper.
Big, compared to the traditional whopper. It could be because it doesn't loose fat when it's cooked.
Taste is great, the only thing it misses is obviously the melted fat taste but it does taste like a whopper.
In general a great and tasty alternative to a meat burger.
Cheers,
B