Nothing "Suite" about it...
Let me caveat by saying I'm a SPG "Gold for Life" and have stayed in every SPG property in Manhattan, even some that are no longer SPG (e.g. Essex House, etc). So please take it seriously when I tell you that the Le Parker Meridien really lets itself and the Starwood Franchise down significantly. 
I'm going to start with the "Cons" here, because these stand out the most
At check-in I noticed the Front Desk staff's daily info. sheet on the desk which prominently read... "Upsell, Upsell, Upsell" Which makes sense, given that I was told "we never offer free upgrades even to SPG Platinum and Gold members" (ummm ok, I didn't ask for one, but thanks for the info).
Elevators - Don't fall for the "view" or high floors - You will be waiting 5-10 minutes for the elevators, which will be completely full. Also, you should know that this building is part residential and the good views of the park are typically private residences. Avoid the upper floors... you were warned.
I reserved a junior suite, which at a mere $600/night, was hoping it would be suitably appropriate. It was horrible. It was smaller than most hotel rooms I have been in and is in serious need of an upgrade (you know those popcorn texture ceilings from the 70's... well that is what you get and is probably the last time this place as seen a renovation).
The gym is in a really dark basement (which was formerly the boiler room) it is spread over two floors and there is not a window in the entire place. Additionally they painted the place black and put in really dim lighting... which makes absolutely no sense if you are trying to get a burst of energy in the morning or evening... also they charge to use the gym (think it was $10.00/time).
Service - Inquired about getting a small tube of toothpaste - "sure, that will be $10.00" which seems odd, given that I stayed at a Sheraton the night before in Nashville and they not only gave it to me for free, but brought it up to the room with a smile. It's the little things i guess.
There are all these signs in the room (which try to be clever, but just come across condescending). "This is a minibar, not a fridge! if you want a fridge one can be provided at an additional charge. If you move any items you will be charged instantly and this will not be reconciled at check out as we will need to investigate." Seriously?... at $600/night you should bring me a subzero if I asked for it, and quit being berating and condescending with all of your signage all over the room. Just poor.all around.
I generally give hotels an opportunity to respond or try and make things right before putting bad reviews on here. So.. i asked to speak to a manager upon checkout, and was told" there would not be one available for 30 minutes". I also wrote to the hotel with all of these comments, to which they responded. "we are sorry, let us upgrade you to a junior suite next time" (ha ha... that's ironic... given that I was complaining about the state of the "junior suite" in the first case).
"Pros"
Location is decent, but if I were you, and wanted to be close to the park, I would try the the London Hotel, Sheraton Hotel & Towers, the Trump, or the Hudson. (Something in there for everyone).
Emma's for brunch is good, but they have no alcohol license so bloody marys are going to be virgin
The secret burger joint is fun and decent, but go off peak and probably order two as they aren't massive burgers (and I wouldn't wait in line an hour for it).