Well, virtually every attraction is better at DLP than WDW.
Do not miss:
Phantom Manor
BTMRR
Pirates of the Caribbean (see a proper version - WDW's is the worst version on the planet).
It's a Small World is significantly better than WDW's and has an America room (do not miss if you are a Disney fan).
Alice's Curious Labrynth, Aladdin's Passage,the Nautilus and the castle walk through with the Dragon are unique to DLP. Explore Adventure Isle
Space Mountain is a must
Also others new to you if you have not been to DL in California are Pinocchio, Casey Jr and Storybookland Canal boats. Also unique to DLP and TDS is Indy, but skip it unless you have done everything else.
Enjoy the different snacks - popcorn has sugar, not salt. The waffles are great too.
Have fun. Personally I have been spoilt by DLP and always get grumpy at the MK as it is not as good as DLP, so we just do the attractions unique to WDW and then leave. Once you experience SM, PotC and IASW at DLP, you may never see WDW in the same light again.
As for Buzz, it is better in terms of how the guns work, but it is not that different than WDW's (the differences in IASW are far greater).