As of ~12 hours into our check-in at Planet Hollywood, my review stays at three stars. While one of our five rooms was ready at check-in time, we were told the other four wouldn't be ready for another 5 hours. No big deal, as Las Vegas is bustling with things to do.
We returned closer to the time we expected to get room access and were told that two of them were still not ready, and one of them was occupied by a "Diamond VIP" guest who had not come down for check-out and failed to reply to any requests of checking out.
Eventually, the rooms were settled and all was well. The rooms are extremely spacious and fitted with a roomy and comfortable bathroom. WiFi is included in the resort fee, and you can probably make do with 5mbps for the most part.
Updates will come as the stay continues.
EDIT: Several days after checking out of Planet Hollywood, my review stays at three stars.
The stay was increasing in quality ever since our check in, but came crashing down when my cousin and her boyfriend got stuck in one of the hotel's elevators for roughly an hour and a half. This isn't the worst thing that can happen to someone in Las Vegas, but you'd at least expect the hotel to comp your stay for what could be a traumatic event to most.
Planet Hollywood offered one night's compensation for their cheapest room to "fix" the issue. My aunt was able to talk them into comping the entire stay of my cousin's room (four nights), which was at least reasonable.
I don't know when I'll be back in Las Vegas. I might stay at PH again, and I might not. At least I'll know not to expect luxury if I do.