So let's get the obvious which has been repeated by multiple people here out of the way. The Groupon is not worth it. Skip it. At the very least read the fine line details that make it very difficult to use them. Moving on.
Winedown is a cool name. The location and venue is nice. Probably could have some cool parties there. The staff were pleasant.
Unfortunately... While there are multiple studies in oenology and psychology that suggest that people cannot taste the difference in expensive and cheap wine, a visit to Winedown will quickly convince you otherwise.
If you don't mind cheap wine (and a headache in the morning) or if you're a student wanting to try something different, this is the spot. But this is definitely not your classic wine bar.