I am iranian and I go couple of times a year mostly when I would like to have kabobs. Their kabobs vary in quality from time to time but are overall OK.
I have been to their buffet three times and it got boring for me, since they do have the same meals most of the time and the quality is below what an average Iranian lady cooks at home, so nothing intersts me in their buffet anymore but I have non Iranoan friends who love their buffet, so it could be interesting for you to try their buffet as a semi-proxy to persian home cooking.
Overall, I guess their buffet is worth trying on a weekday(when cheaper) and you might like it, but do not keep your expectations high.
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