I haven't stayed in a Paris room for a long time. The ultra hip room is very nice. I would stay at whichever casino you like to gamble at.
Paris rooms IMO are a little better; nicer materials used and more of a classic style. Ultra Hip was fine but felt a little cheap and half-assed. Bathroom was bigger and better in the Ultra Hip though. Can't go too wrong either way, I'd base it on which resort you prefer.
PH is supposed to have refreshed all of their rooms. Paris red rooms are becoming worn and due for a refresh, Burgundy are the refreshed rooms. PH casino has a good vibe towards the younger set, imo. Paris a bit more sedate. I am in my 50's and prefer Paris. If I was in my 30's or younger, I would go with PH. The fountain view at Paris is pretty sweet, if that matters. Enjoy your trip!
Paris has renovated most of their rooms and should have all the rooms renovated soon. Even prior to the reno, I prefered the Red Room. To me, the ultra hip rooms are too dark with not enough lighting.
I would have to pick Planet Hollywood over Paris. The new Ultra rooms are much brighter and the fridge added to the room is a nice touch. I like the atmosphere of the casino more than Paris even though I am older than their targeted audience. Mark