I did, and I paid for it.
Although the venue was in its last hour of trading on a slow Sunday afternoon, the kids who ran the place (all staff seemed to be 15-20 years old) seemed to be late with everyone's orders! I waited 30 minutes for mine and was about to walk out when my meal appeared.
Thankfully it was both cheap and yummy: Manna Haven lists a $10 special on its deals board every day. My special meal was a slice of the moussaka with some salad. At a third cheaper than the real moussaka item on the menu, it was not bad at all, in terms of both size and flavour. However, it was really the passionfruit cheezecake that made my lunch and caused me to forget my earlier hunger. It is still rare to find almost every dessert in a vegetarian establishment being vegan, but this is the case at Manna Haven.
All in all, I will come back here in a less-hungry state next time, give the staff plenty of time to get their act together, and enjoy more of their wonderful menu. I hope that the staff work out their timing issues and put in a more professional appearance.
Note that their website is great - clear and informative - and will allow you to make up your mind about what you want to order before you arrive (if you get there hungry...)Pros: Lovely, bright atmosphere, shady outdoor seating, great food choices
Cons: slow staff