Alright, as I have been here a little over a year and have renewed, here are my thoughts. The Premium annual pass is worth the extra money for 4 reasons. The 2 water parks, Disney Quest (I have a 7 1/2 y/o son) and you get a 20% discount on any merchandise you purchase in the parks or downtown.
As far as a Universal / Disney pass, there is none. I think what you are hearing about is the Orlando Fun pass or something like that. It covers Sea World, Universal and Busch Gardens. I have not been to Universal yet since we moved here. We are going at the end of the school year for my son's end of year reward. Busch Gardens is better in Williamsburg. Sea World is fun, but I can't do it more than once in a year.
There are many different Disney Passes, we aren't DVC, but figured out that if you go once a week for a year, it costs a little over $9 a day, which isn't that bad. There is a pass that is a lot cheaper but as you stated does have black out days. The regular annual pass doesn't get you into the water parks ($45 per adult I think) or Quest which is about the same, and you only get a 10% discount.
I hope this all helps. Let us know what you decide.