Stayed at Marquis. I was there last year.
It's a wonderful hotel. Rooms are spacious, and this year it felt like we had no issue getting 2 doubles (last year there was a bit of an issue getting them and we ended up with a king+rollaway, and I know others weren't as lucky).
The staff are wonderful and handled a kind of complex rooming situation on our part very well (one person chose to extend the stay in just one of our two rooms worth of people) and the room service was very accommodating.
Biggest gripe is that "because of traffic" they decided to only allow Valet and taxis into the main pull-off zone in the front of the hotel on Sunday. My husband was unable to bring our car through the place we were dropped off (and last year we were picked up there too) so we were told to take our no less then 6 huge suitcases over to the other side of the hotel to be picked up.
That should 100% be conveyed to people before they assume. If you are changing things up from the norm you should have staff notifying people or signage made.
The location for having bags held was atrocious. They put them in the hallway near the tunnel that people are still trying to pass through to get to the convention center on Sunday. There seemed to be plenty of unused rooms in the M1 level so I'm confused why they made that choice to have them semi-unattended in the hallway. At least in a room you could somewhat secure them.
Still, the staff is great, the location is amazing, room very tidy and the price is fine since we're sharing rooms. Hope to be there again next year.
I still am going to complain about the noise, but it's less the hotel's fault and the fact that for some reason Otakon con-goers can't be mindful of each other after midnight. e_e