I stayed at this hotel the second week of april due to a conference that was taking place here.
I must say the hotel has a great location specially if you are not renting a car, it´s just in front of the Onmi terminal and from there you can have access to pretty much anywhere in Miami.
However the hotel is a little overpriced.
The rooms look kind of old, and the carpet was terribly dirty. Bed was comfortably and the view I got was excellent, partial bay view and partial city view.
The service was not good at all, from the mess up check in until the 40 minutes waiting for a band aid to get to my room....
I´m coming to Miami on november again and I will definitely not stay here.

This is an 'average' Marriott, so still more than acceptable, even if not likely to be the best expereince in your life.

The hotel interior looks a little dated (lobby, corridors etc.) but the rooms were decorated to usual marriott standard.

Managed to get a move to a room facing the bay on 26th floor and the views were of course amazing.

Staff were friendly enough though I found that the restaurant staff were very obsessed with making sure they got the 'right' gratuity. I know gratuities are important n the US but here they seemed overly concerned with this.

We used the pool once as well and it was fine, though a little cold.

I was a bit annoyed that over the weekend they closed the club lounge (I'm a Marriott elite member so this provides me and my family with free breakfast/snacks). This struck me as an unnecessarily cheap thing to do. When I complained I was give some breakfast vouchers but had I not done so I wouldnt have had any.

Didnt expect to have to pay 25 USD to park per day (actually I paid 28 for lobby parking) but there is little in the way of competeng parking nearby and that which is available is same price.

So overall it was fine - Marriott's usually are - and it wouldnt be a disaster to stay there again with my familly - but i'd probably look elsewhere first

Clean room , upgraded bedding, with excellent view of the bay. We had booked with a special AAA rate of $130 per night, I can't imagine paying the online rate for this hotel, it was nice, but not up to the price listed for the room. The mall area between the Marriott and The Doubletree had several shops for items you may have forgotten and a nice deli/bakery.The front desk staff was exceptional in giving us info for visiting South Beach for dinner. I would enjoy staying here again before a cruise. We checked out, grabbed a cab and were at the port in about 15 minutes total.

Initially I was pleased with the Marriott Key Biscayne. As others have mentioned the rooms were outdated, but every room appeared to have a balcony and a great view of Downtown Miami as well as a view out to South Beach. You really couldn't beat it. The staff upon check-out was extremely friendly. A seemingly good stay until I realized I forgot my toiletry bag at the hotel.

I called and spoke to an extremely unhelpful Security person. He was not concerned about my lost bag until I called again the next day and asked to speak to management (then he aimed to please). I realize it wasn't their fault I left my bag and thankfully there wasn't anything of great value in it, but the bag was important to me and I expected them to act in kind. The manager did call back and apologized for the poor service I received. He told me he would do one more check for my bag and would call. It's been two weeks and I've never heard anything again.

This incident soured my pleasant stay. I would only stay here again if it was free or by using my Marriott points. The only positives were the balcony views and the bartender who made great drinks.