We've done both and they both have good points to do each. I enjoyed the wishes cruise because we were able to cruise bay lake and the seven seas lagoon. The music was out of sync but the view and closeness to the loading docks in front of MK was nice. Have shared every cruise with fellow Dis'ers.
The Illuminations cruise was nice, but if the winds blowing in your face you will eat some smoke. THe chance you take. But the inferno barge warms you right up on a cold night. We cruised around the world showcase and got some good video.
Overall, now that the prices have gone up and the number of people I think are limited that can go on cruises will curtail our cruises. We enjoyed them, but not at that price anymore. I say do both and form your own opinion. We do that for most things at WDW. Everyone's expectations are different. Have fun with whatever your choice.