I have used vegetarian cheese (surprising how many restaurants insist a dish is vegetarian when it got ordinary cheese in it) and I found it a bit rubbery as opposed to the crumbly texture you can get with "normal" cheddar. I'm not vegan/vegetarian but have friends who are so I make dishes for them when they visit. To be honest, I find a full vegan diet terribly limiting (no dairy, no ordinary cheese, no eggs etc) but if you are doing it for ethical reasons like my friends, then I make an effort to find something suitable and hopefully tasty for them to eat.