I've only been to Chez Guevara once, I think it was either a Friday or Saturday night and the place was slammed. It took a long time to get seated and it took a really long time to get our meal. The staff was friendly and attentive with drinks but I didn't think the food was worth the wait. It was fine but nothing spectacular and the vegetarian options were limited and there was only one vegan option on the menu. I would recommend going on a weeknight instead of on the weekend, I'm sure service would be faster on a slower night of the week.
Cons: long wait, limited menu for vegetarians