I haven't taken a class from any mentioned, but I have purchased gear from Maximum Scuba. A big draw for me is that they match online prices. Granted you pay tax, but you will save shipping, and some items like Oceanic dive computers can be swapped in the store if they have another unit in stock for warranty issues, so having a local dive shop in my opinion can be better than online retailers in some situations. Plus, having owned a small business, I try to support my local economy. Second, I received good service after the sale because I needed some adjustments to my regulator & I was so glad I didn't have to ship it or pay someone to work on something I bought online to avoid shipping. Another reason you may want to consider Maximum is that if you buy all your gear from them, they will give you your Advanced Open Water class free.
This is an experience I had with people from Just for Divers. Well, I'm about 99% sure it was Just for Divers. We were at the Blue Lagoon in Huntsville & the group's instructor was in a red Dodge truck if memory serves me, pulling a small enclosed utility trailer that had Just for Divers on the side of it. I was reading it from across the small lake at the Blue Lagoon, so there is a very slight chance I read it wrong but considering there is someone that operates under that name in the Houston area, I'm confident I am right.
My colleague & I were doing our open water portion of our dive class on July 30-31. That Sunday, the 31st, we were diving with out instructor & his grandson whom was also taking lessons. The first incident was that we had what appeared to be an entire class descend on us while we were on a platform doing drills. There's no way they could have missed our bubbles from the surface & any instructor with common courtesy would have taken his class to one of the other 3-4 platforms that were not occupied. Luckily we were about done & were planning to navigate over to the sunken sail boat using compasses & we left. When we got to the sailboat, our instructor had us do some more drills & I was in the middle of taking off my BCD & putting it back on. While I had my BCD off, some guy swims right up on me, basically pushes his way past my instructor to swim thru the boat with about 4-5 students in tow. His students were so close to me I had to elbow & bump into them to finish putting my BCD back on.
These students looked like they were a youth group or something because none of them appeared to be over about 16-18 & some looked as young as 12 years old. Who ever this guy was, he was not setting a good example to these youths as to how one should conduct themselves when diving around other groups of people. I really wanted to go over there & confront the guy, but with age & wisdom, I know myself & I know my temper, so I thought it best to just not risk getting kicked out of a place I plan to camp & dive at in the future.
As for Sea Sports, I've heard mixed things about the shop. When I went to their Westhiemer location, I was greeted warmly & my friend had to buy his mask & snorkel & he got good service. I can't comment on the classes.