I would like to start on a positive, the accommodation is set out very well.
Thats the positive done with lets now focus on the bans "DIVING" experience. As an experienced diver going along with my family on their padi open water course, i would have expected this to have been an enjoyable experience.
Well used to getting up early to catch the morning boat with other resorts, this was not an issue- waiting nearly 2 hours in the mornings whilst bans circus of staff/apes/instructors sat around looking at bags of dive gear, regulators etc as if they were a university challenge complexed physics question, scratching their heads, this was the first issue.
once on the boat- the dive briefing.
How the beaches are made!
Why alcohol is poison and soft drugs are not!
How eating pasta makes a healthy body like the 'instructor'!
Alarm bells started ringing in my head- Have my family learned enough to safely dive? what kind of dive school is this? To the point- its not its a FACTORY. "give us your money and we'll 'certify' you".
Having had the instructor lecture nazi style in front of the whole boat (family included) on a minuscule extra kilo of weight i had on (due to a new wet suit and 55meter deco dive done the previous day) really put the icing on the factory made cake.
In conclusion if you actually want to learn to dive, have a better community and service there are a number of schools further north on the beach that supercede the quality of bans resort.
The bar and restaurant are a joke also.

I stayed there with several girlfriends over the summer on our tour of Asia.
They wanted to dive but I didn't which meant we got a really good deal. we decided we wanted to stay in a nice room near the reception.
Our room was newly renovated with a lovely bathroom, tv in the room with loads of american channels, our beds are nice and there was a fridge and a view of the sea from our private balcony.

at night the resort turns into a night club area, there are numerous clubs along the sea line.

the staff at the resort are not that friendly. They can be very unhelpful.

there is a nice walk away with shops and restaurants beside the hotel area and a swimming pool with sun loungers and fluffy white towels.

I'm surprised with all the negative reviews of Ban's. My experience with Bans was similar to all my other experiences in the south of Thailand. The people there are tired of tourists and they are rude and disinterested. Ban's is no exception - and no worse than anywhere else I stayed. While at Ban's, I stayed in a budget room that was clean and acceptable for the price (1/2 off since I was in the diving school). I think the more expensive rooms are closer to the beach and bar and, therefore, are more noisy!

In my experience the hotel staff was acceptable, but certainly not accommodating. The real problem I had was at the restaurant. It was totally unacceptable!!!! The food was marginal and you honestly had to beg to get a menu or to get anyone to help you. If you managed to order, it might take 5 minutes to get your food, or it might take 1 hour. I quit eating there after my second day -- but found several of the competing restaurants to be almost as bad.

Having said all that, my experience with the dive school was very good. I had the best instructor imaginable - his name was Ronan and he was Israeli. He was fantastic!! My dives were not overcrowded and Ronan did a very good job of maximizing our time in the water and our experience while underwater.

Koh Tao, generally, is very popular as a European backpacker destination. It has cheap accommodations, very cheap diving schools and lots of drinking and having fun. If that's not what you are into, I would strongly recommend trying someplace else. I'm only 36 yrs old and I felt like an old man there :-) Of course, if you have any aversion to thousands of <25 backpacker-types, I would avoid Thailand all-together!!

Overall Koh Tau is a wonderful place but choose where to stay and/or dive very carefully. I stayed at Ban's for 2 months to complete a Divemaster course & I found the staff here to be extremely obnoxious, arrogant & very, very rude, both the Thais and the western diving instructors. Ban's completely ruined my experience of Koh Tau to be fair. I've never been as badly treated nor spoken to in such a rude manner anywhere else. Horrible place & people.