We stayed at the JW Oct. 16-19, 2009. Our room was on the 19th floor and, like all rooms in the hotel, had a nice view of the coastline.
The public areas of the hotel are extremely nice. Marble floors throughout. Hotel security is always present (we didn't feel that the hotel was in a particularly unsafe area to begin with).
The staff were always attentive and cordial....without exception.
Overall, the room was very nice. It was definately spacious and well furnished. The bathroom was nice with a seperate shower and tub, and two sinks.
Because everyone has accurately portrayed why this is a nice hotel, I will not go in to those details, though many are definately warranted!!
There were a few items that "put us off" slightly.
1. This was the first Marriott hotel that I have stayed at where I had to pay to use wifi, even in the lobby.
2. The breakfast buffet had a huge selection of food items. However, none was particularly fabulous. Both of our omlettes tasted heavily of cooking oil (more so than the actual egg taste). Marriott hotels usually pride themselves on food presentation. Again, the food variety was excellent! The preparation was not so great! And at $22 per person, the price was definately not worthy of the quality. We went across the street to Larcomar shopping center and had a similar quality breakfast for $4 per person.
3. We noticed that the walls under the desk and along some of the walls (near the ground) were full of shoe scuff marks. The hotel did choose a VERY white paint to paint the rooms with, so naturally it's going to show everything.
Again, I am pointing out some of the flaws to try to present a balanced picture. To read other posts, this is just a perfect hotel in every way. We have to slightly disagree given the above mentioned items. With that said, we would certainly return to this hotel if we had to return to Lima. That too should tell you something about our review.
In summary, this is a very nice hotel! Staff are friendl and professional. The location is pretty good. It has all amenities one could want. The prices are just a little steep for what you get. So don't let this review disuade you from staying with them. Just have your eyes fully opened to the fact that, despite seemingly perfect experiences by all, there are a few minor bugs for the JW to address.

I have had the pleasure to stay at the JW Marriott for the past 5 months for at least 3 weeks a month. It has become a home away from home for me and the service has been wonderful. The executive level always has good food with smiling faces ready to help with anything. Also the concierge and front desk are very helpful, whether I need help with reservations or help with laundry, they always are there ready to help. Even with a few issues that I have had, they have quickly remedied the issues without questions. Thanks for making our companies stay here very nice. All of you are great.

Just to make something special in weekend, but i found a pretty suite, and good service ¡¡

After a few months backpacking around South America staying mainly in hostels and small B&Bs, I decided to splash out on staying at the Marriott while I was in Lima for 2 nights, mainly because I'd heard a few bad things about the city and wanted to stay somewhere safe and more upmarket , plus they had a good value weekend offer that made it more affordable to stay there. It was great to stay in lovely Miraflores and the hotel has a particularly good location right on the coast, with ocean views from every room and just across the street from the restaurants, shops and cinema at Larco Mar. I'd requested a high room and got put up on the 18th floor with brilliant views. The room was fantastic with a REALLY comfortable bed, lovely bathroom and the largest TV I think I've ever seen! They arranged my transfer from the airport in a rather nice Mercedes and the driver was actually waiting for me at the luggage carousel in the airport! Great service...The breakfast was the best I've had in all of South America, though the price was pretty special too! My only complaint was how much extra they charge for additional items and services. The cheapest hostels I've stayed at in South America have all offered free internet and most have free Wifi too, but the Marriott charges you quite a lot to use these, which is a bit annoying when you've already paid so much to stay here. Though I guess that's why they are a prosperous international chain! Getting a few essential items of clothing laundered here cost more than my previous night's accommodation cost in Arequipa! But again, probably standard for this type of upmarket international hotel. So my only real complaint is that if you are going to charge for using the Wifi, please get a better connection - it kept crashing...And 24 soles for a bottle of mineral water...crazy. But still, it was a lovely hotel and worth the extra cash for making my stay in Lima so pleasant.