I like Quorn. While it’s not an exact substitute for beef or chicken, it’s not bad and it’s a heck of a lot better than TVP or tofu. I much prefer to use Quorn mince to make burritos than the questionable substance that is real British beef mince, and the chunks (of a chicken-like consistency) also cook up well in Mexican or stir-fry recipes.
I’ve eaten a lot of it over the years and had no adverse reactions, which is also more than I can say for some of the meat I’ve eaten (campylobacter, anyone?). I know some veggies won’t eat Quorn because it contain non-free range egg whites, but I’ve got no complaints at all.