I've been booking UO hotels with the AP discount, and our upcoming stay is approx 25%off. I can't remember if you have the CSP or CSR but it might be worth it to book the discounted rate and cashing out UR's and putting the room towards an msr. I'm sure you can do the math on that

the AP isn't required to book beforehand either. There's a thread on the universal board with a link to book ap rooms.
Also I wanted to point out that last year we upgraded our 3 day park to park tickets to seasonal AP's for free for the adults, $10 each for the kiddos. So our admission this year is free! Definitely worth checking into even if you're not sure you'll be back in a year.