Yes, I have been on jazz cruises before and they are great! I don't know who is putting it on, but Dave Koz is involved with a radio station here in San Diego (KIFM) and everything they do is top notch. I would sure look closely at it.
I got to chat with Dave Brubeck for about 20 minutes one time on the QE2. His "TAke Five" was one of the original surf songs and for me to actually get to meet him and see him perform (with his son) was memorable.