O.B.s = Neighborhood bar on steroids. 3 Years ago it was a very small tavern. They bought a big building and moved a couple of blocks. I still enjoy going there once in a while, but IMHO they lost their identity when they moved. O.B.s is probably 20 minutes from the boat show (10 minutes to get through the city to hwy 40, and 10 minutes out 40). It would be a great place for a get together if you have a big group and you want to pull together a few tables drink some beer, and bull**** all night. Cross your fingers maybe Alicia will be behind the bar .
Most St. Louisans stop going to the landing when they're about 23. However the place is packed with out of towners and kids every weekend. Stay on the beaten path and you won't have any safety issues. The great thing about the landing is that it is within walking distance of the boat show. You also have multiple bar choices, everything from a micro brewery to the latest dance club.
Disclaimer: It looks like I'm out of town that weekend so I probably won't make either. Just trying to shed some light on your choices.