Long-term pescatarian here: the beyond burger is to me the most delicious of all "i'm not meat and never will be" fake meat products. The impossible burger on the other hand disturbed me: I tried it twice at 2 different locations in NYC to make sure, and both times I felt like I had meat. I still remember the smell of the blood-like heme. I did not enjoy it. I'm not sure the impossible burger is a good idea for vegans/vegetarians. I welcome it for healthier options for meat eaters however.
I'm a burger lover who tolerated the soy burgers better than a lot of folks in school. They tasted like crap, though. Unlike meat in many ways. It was all these HN comments that made me try the Beyond Burger. It was different.
It looks more like meat, sizzles like meat, seemed to have texture of meat, and mostly taste like meat. Not quite meat, though! I'd say main difference, which could've been how it was cooked, was that it was soft and crumbly. It about fell apart vs how most burgers are solid. That's a drawback for most but better for a certain niche in my testing. I might try to sell them that finding, though, given it would expand their market.