I just remember Solo being retardedly ridiculously expensive for what it was. And, even with the 30% off, they add a 20% service charge to the RSVP for groups 6+, so there goes most of that. Last, Solo doesn't seem like the best place for what this would be... seems a little more "buttoned-up" to me, whereas the others I mentioned aren't.
That said, if that's where it is, that's where it is.
Personally, I don't mind any of the three, but for the cost-conscious among us (wait, that should be most of us), I'd think Mendy's in the city would probably be a decent choice. There's actually one on Third Avenue which is in a public atrium of sorts which actually might serve DO purposes quite well. Only potential problem is that I'm not sure what time it closes, especially on a Sunday.