The restaurant side of 21st Bar and Grill is pretty decent, featuring artwork by local artists hung nicely on the walls. However, the bar side is indeed pretty divvy. Forget about that and head straight back to the deck. Their patio is AMAZING!
On to the rest... Ok, I don't mind dive bars, I fit in just as well there as I do at a nice restaurant in The Pearl. It sounds like some of the previous reviewers (is it more than one, or just someone who has a serious beef with the owner) may not enjoy dive bars. The weird thing is, once you make it past the deteriorating bar to the patio out back, it's like walking into a completely different place. It's really peaceful and nice. They have an amazing Koi pond, with a waterfall and incredible japanese style landscaping... Picture drinking a beer, and/or having a burger in the Japanese Gardens.
The wait staff was very pleasant to me (on the patio). However, I did witness the bartender yelling at a customer inside, I don't know if she had a legitimate beef or not. But like I said, forget the inside and head straight back to the patio. You will love it... Unless you hate beautiful things, good food, nature, and an escape from the hustle and bustle just outside the building. In that case, I doubt you're happy anywhere.
Pros: Amazing back patio, good food & drinks, friendly wait staff.
Cons: The inside needs a makeover, the bartender needs a timeout.