We have only sailed Disney once, and we LOVED it. For us, there are only two negatives. First, the lack of differing itineraries. Ports are a major reason for us to choose a cruise, and Disney spends the vast majority of its time at the same ports over and over again in the Caribbean.
The other factor is price, particularly on those 'different' itineraries, such as Mexican Riviera and Europe. For the price of a Disney cruise in a regular outside cabin, we could take a longer cruise on Princess in a minisuite. That's really the main thing that has held us back from cruising Disney again.
FWIW, we visit a Disney park (either WDW or DL) every year.