City of Emeryville Aquatics Center
We also tried group lessons with my son (he's 6 now) and he didn't respond well to them. Last year we tried private lessons through the Emeryville Aquatics Center and he learned to swim very quickly. The instructors were all pretty young - late teens/early 20's - and very good with the kids. We especially took to Jackie and did 12 lessons with her. It's very affordable - I think we paid about $22 per lesson for 30 minutes. There are other instructors teaching one on one in the pool at the same time. It is an outdoor pool. https://www.ci.emeryville.ca.us/1256/Aquatics
Emeryville pool has private weekend lessons. Patient teachers. Nice pool.
Emeryville community pool
We've done a number of swim classes in the area and it depends what you are looking for, your child's experience level, timing and price. I can't say that I'm familiar with the classes at La Petite Baleen so that would make my response less useful but I can tell you about our recent experience with our 4-year old.
We got a groupon for Aquatech and liked the intro class. It was just 2 kids per adult and the facility is clean and the instructors are all good. We wanted classes on the weekend and it was great but we saw that it would be a long time before our child felt comfortable in the water. We could have continued but the cost was too high for us without the groupon.
Over the summer, we had a great class at Roberts Pool in the Oakland hills and it was in the evenings M-Thurs for two weeks. It was great because he was able to really make progress each day as opposed to waiting for each Saturday and taking a step back.
Currently, we are taking a class in Emeryville and it has less instruction. It is a parent/child class (the others were with just the toddler in the pool) and it is definitely focuses on singing and free play. It's great for the parents to interact with the kids in the pool but again, real swimming seems a long way off.