I'll post a quick reply, because I actually had the opportunity to visit several of the clubs and bars last Saturday night.
Let me preface this post with a quick explanation: my wife, my two best friends, and I visit HHN every year (minus the last two years). Ever since our first trip in 2005, we have been waiting until we were all 21 to visit all of the CityWalk venues. Well, this was the first year that we went where everyone was of age. Needless to say, we may have over-hyped these places in our minds over the years. Here are my feelings on each place that we visited in a quick review-style format.
The Groove - So this obviously seems to be the signature spot for nightlife entertainment at CityWalk, at least according to the advertisements I've seen. For that reason, this was the one we were looking forward to the most. That being said, we were a bit disappointed. Compared to our expectations, we all agreed that this place was very small (this turned out to be a recurring theme). For a city like Orlando and a resort like UO, this place is TINY. While I have been to overcrowded clubs in the past, I just couldn't wrap my mind around the decision to make this place so small given the number of people who visit UO. Aside from that, I didn't really find it to be much to look at. The different "rooms" were nothing more than places to sit, and the dance floor and music setup was generic at best. We stayed for about 15 minutes before losing interest and moving on.
Latin Quarter - Again, this place was smaller than we thought it would be, but I really liked the nighttime sky inside of the building, as well as the bit of theming that was present. Granted, if music of Latin American origin is not your thing, then you may not find this place all that exciting. We thought it was refreshing compared to the typical techno-centric music of most clubs you go to. We definitely had more fun here than at the Groove, but still only stayed for about 30 minutes before leaving.
The Red Coconut Club - Boring. Uninteresting. I could see that they were going for a kind of swanky lounge feel, but I don't think it worked. As before, this place was also very small.
The Rising Star - I will echo the sentiments of some earlier posts: most fun we had all night. No one in my group chose to take to the stage, but we had a ton of fun singing along with the brave souls who did. The place is set up very well, and I was very impressed by how big it was, given that its still a karaoke bar at its core. We stayed here for a little over an hour, at which point the entertainment concluded for the night. Honestly, this is probably the only place that any of us showed any interest in returning to.
To end, I just wanted to add that Margaritaville was also pretty awesome with an incredible live band last Saturday. I wish I could remember their name, but they did an excellent cover of Devil Went Down to Georgia, complete with fiddle solos. Anyways, if it were me and I were you, I'd say grab a Cheeseburger in Paradise and a margarita at Margaritaville before heading to the Rising Star for drinks and entertainment.