Getting there - but they need better housekeeping staff
Got a nice rate at BookIt.com to stay here during Toy Fair. I like trying out new hotels and Flatiron is still in a "soft opening" right now. 
The Good: 
Check in was great. Front desk staff was very helpful, and even gave me a card of their business manager to contact about show rates going forward. The room was nice. Had a Madison Park Double (#804) and room size is nice with the two beds. Turn down service (they close the electronic curtains) is given as well. It's 2 blocks from Eataly, which is great for food and close enough to Javits. Cabs were pretty easy to catch on 26th, too. Platform beds were super comfy. Lobby is gorgeous with that fish tank.
The Bad:
Housekeeping. Upon arrival we noticed a LOT of dust hanging from the bathroom vent. There was a housekeeper in the room next door, so we asked her to swiffer it as there was a damp/moldy odor. She refused. Told us to call the front desk. We did, they sent someone up to clean it. The TV only had standard channels and cable, the "on demand" button did nothing. It's possible they didn't hook it up yet and I wasn't at a loss watching TV and HBO anyway. But there was no TV check out, that I normally do. Two days before I left the housekeeper "cleaned"... took all the soap, shampoo, etc that was only half used, and didn't replace any. So I had no bar to even wash my hands with. But she forgot to dump the trash bins in the room as well. Not professional. Told the front desk staff, and they said they'd send stuff up while we were out to dinner (Valentine's Day). When we got back, shampoo/conditioner/lotion was there... but still no hand soap. Asked at front desk again. They said they'd send it... but none ever came. Checked out the next day. 
I'm not sure I'd stay again and it was a nice hotel. I know they're new, but asking for something as simple as SOAP shouldn't take 3 tries or more.