I went down on the premium plan last year, and I wanted to offer a couple insights:
Last year, it included the tip. I don't know if it will in 2008, we won't be using it next year. But I know the
DDP/ Deluxe DDP do NOT for 2008. I just think you should double-check that.
The premium plan includes restaurants that aren't on the DDP. Check the individual restaurant of interest, but for example, we had breakfast at Rainforest Cafe outside AK one day. We were treated like royalty--they don't take the DDP.
The premium plan used to include specialty drinks, like a smoothie with breakfast. Again, check the latest brochure. There seemed to be CM confusion about this, it was different from the DDP.
In addition, we encountered quite a bit of confusion among the CMs relative to included activities on the premium plan. For example, my kids wanted to try parasailing. As an aside, it's included, it's behind the Contemporary, it was fabulous! Absolutely #1 in my kids' book! But anyway, the Cm's were so clueless on this! First, we were told it wasn't included (brochure specifically listed it). Then, we were told to go to the Poly waterfront (we were at the Poly) to sign up--again, not true, you call over to the Contemporary. There were a few other things, too. In the end, we went, the kids had a great time.
My point in all this is, Disney employees seem to have very little familiarity with the premium plan. Having been on it a few times, I knew where I was coming from. Things were straightened out fairly easily, but I was real surprised that the CMs made so many errors--especially since, as you know, it ain't cheap, so they're dealing with the high $$ spending customer--you'd think they would try a little harder to know the plan details. But, that said, we loved the plan, we had a great time each visit (I think we've been 4 times on the premium plan). I can see where it would be great for a special honeymoon experience.
I wish you luck--read the brochure! Memorize it! Don't be afraid to politely question someone who gives an unexpected answer!