We go to the place in East Tamaki

and love it. It is $12 a lesson, and, really, to go to a lot of public pools (especially because both myself and DH want to be there) it costs about the same. (I was shocked at this over the holiday period when I wanted to keep DS's water familiarity up.)
The 10 lessons in 10 days is just a suggestion -- we didn't do that - nor did most of the people in DS's group -- and it's fine.
The thing that I really like about it is that the pool is chloride and bromide free -- and it makes such a difference! Some of the public pools I went to I felt the chlorine sting my eyes even just going in -- so I wouldn't let DS put his head under the water there -- but it is great at Splash Central.
Also the pool and the pool surround is deliberately warmed to a warmer temperature for babies -- again, I was surprised how cold the other public pools are.
The advantage of starting at the age you are (around 6 months) is that they haven't learnt to be afraid of the water yet -- I've noticed the difference even with babies who start at 18 months -- they are a lot more nervous.
And I think the teachers are pretty good -- they explain their reasons for teaching things -- like back floats and returning to the side of the pool, etc. There are a lot of things I wouldn't have thought of.