My wife and I have enjoyed Abigail Street three different times now, once with a group of friends and twice as a couple. On every visit, the service and food have been top-notch. It's not very big and it usually fills up fairly fast, so get there early. You can get full food service at the bar if you can't get a table.
Our personal recommendations are the octopus, the beet salad, and the churros. Yes, absolutely the churros. Since this is a tapas/mezzes spot, you can easily experiment with items you might not normally try. You won't be disappointed. Everything we've ever tried has been great.
The only potential negative is the high sound level, but many people will consider that a positive aspect of a lively engaged crowd.