I'm not as interested in day of the week as I am in purpose. (Although on a weekend for me Sunday would likely be better than Saturday.)
Perhaps if we figured out some kind of reason to get together, rather than just say we're all going to Dave and Busters. Maybe sometime someone from the smart center in Round Rock would come speak to us about something. Or maybe on a weekend day we'd all caravan somewhere like the winery tour that was talked about.
Perhaps even just having some kind of agenda for the monthly meetings that helps plan special events? Post the agenda in advance so people know what is going to happen?
Just sitting around at a noisy restaurant talking isn't that appealing a prospect for me most of the time. Also, I'd suggest rotating meeting locations so that sometimes they're a little closer to those of us who get nosebleeds when they go north of the river ;). For me, it's close to 30 miles round trip to Dave and Buster's. That's a big time consideration, especially when meetings are still at the tail end of rush hour.
Just my 2 cents, which in the current economy is probably worth much less.