Are the kids strong swimmers?
If the kids are not, will seeing Really Cool Slides without being able to use them mess up their fun?
If it will, of the Disney hotels, go with PPH. PPH's slide doesn't empty into the pool, so there's more leeway in who can go on it. The other pool slides empty into the pools, and you canNOT have someone waiting at the bottom, canNOT wear a flotation device, and the sliders must be able to swim away from the slide *immediately*.
For DS's 5th b'day we stayed at DLH, and the pool was a bit of a disappointment. Can't climb on the pirate ship (or even touch it), can't slide on the big slide...no fun! He did get over it and have fun on the tiny slide, but that's a bit crazy for the *parents* waiting at the bottom, jockeying into position as your own kid comes down, etc etc.
By far our best hotel experiences onsite at
Disneyland have been at PPH. Bigger rooms, basic pool that works for a littler kid, etc. Plus, they pump the smell of suntan lotion into the lobby area.
Coolest part of DLH was the grounds, and the remote control jungle cruise boats...but you can (pay to) drive those without staying there!