We did a cage-diving trip off of Isla de Guadalupe, but with Nautilus Explorer, so I can't comment on your vessel or specifics of your itinerary. I can say, however, that it was an amazing trip, and a definite highlight of my diving "career." The sharks are simply gorgeous, and Explorer did nothing to get them riled up or "performing" (I think they threw one tuna head in the water so there was an attractive smell, but that's all). It was really fascinating watching the various territorial displays and subtle interactions between the individual sharks. They just cruised around, seemingly a bit curious about us but not anywhere close to a Shark Week-esque frenzy of activity.
The worst part (for us) was the trip out; we were headed SW out of Ensanada, with a constant wind out of the north, and fairly heavy seas. 30-35 degrees of roll for a 26 hr trip does not make for a happy ship. On the plus side, I discovered that I really don't get seasick, and once we got to the island we were on the leeward side and everything was gorgeous.Be sure to take your Bonine, Dramamine, Whatever-ine.
Here's my Flickr album from the trip. I got a couple of decent shots with a silly little Nikon CoolPix point and shoot (after a few pointers from one of the crew; I particularly like the one of Shredder). If you're any kind of photographer you should be able to get some great photos. If you can't access them from my Facebook album I'll see if I can throw them up on this site somewhere.