I'm an omnivore but I've had this before and enjoyed it a lot. My friend who'd not had haggis of any type before really enjoyed it. (They didn't want to eat offal).
In terms of vegetarian haggis this is the best I've tried on the market. It really does taste like the real thing and has an authentic texture too -- whilst obviously being made from veggies, not trying to be a meat substitute. Excellent!