My only experience there is with the Don Jose. Did a week with them a couple of years ago and it was wonderful! I think you book them thru Baja Expeditions (I was doing this trip last minute as part of a REEF field survey so the details of booking weren't something I had to deal with too much).
The crew is absolutely fantastic, the food is great (even though I'm a vegetarian they had no problem accomodating me), and in my limited warm water experience I thought the diving was great. We were there in October so didn't see any of the big pelagics but saw a lot of life at every site we visited. We ended up not being able to go as far south as we had intended because there was hurricane activity. Don't know when the best time to see the big critters but I'm sure someone else will pipe up with that info.
One of the best things about this operation is that they are VERY environmentally aware. But if you are looking to do spearfishing this isn't the operation for you-it isn't allowed.
I did a report of the trip which you can find (if you're interested) at pnwscuba.com. From the Home Page, go to Dive Professionals, then Georgia Arrow, then Baja REEF field survey report.
Hope you have a great time.