Since the closure of Therapy has caused us to keep our eye out for hidden martini locations we popped in to Sienna Cafe on our way to Cosmos. There was an infused martini special and it was worth the stop. As previously mentioned in other reviews, it was pretty dead in there on a Saturday night around 7PM.
That said, you can take your pick of bar seating, lounging around on some comfy couches or opting for the small patio in the back. If you just want to have a quiet conversation with some friends or you can't get a group into some of the other more packed places for happy hour, I'd say stop on by and take advantage of the drink specials.
I can't say I'd commit to a meal here until I tried some small plates or appetizers first.