My wife and I stayed at this hotel for 3 nights whilst on vacation during June 2007. Please find my feedback / comments below:

Booking
We booked on hotelclub and got very reasonable rates (+- USD 130 pn without breakfast) that had left us quite excited. Confirmation process was smooth.

Check-in
We arrived late at night after a flight delay. Staff on hand were friendly and polite and processed our check-in pretty quickly.

Room
The bedroom was comfortable - the size you'd expect for this type of hotel, although the bathroom could be a little bigger. The bed was comfortable and the air-conditioning worked fine. The fridge was very small, not allowing us much space to store things we had purchased. Our room was serviced in the late afternoon which annoyed us as we'd make early starts and want an afternoon nap prior to heading out for the evening.

Concierge
This was a huge let down for us and has significantly pulled down this rating. We requested concierge to book a tour for us (three weeks prior to our arrival) for the first day we were there and get some museum / entrance tickets for the second day. We had confirmation emails indicating both would be done.

The first day tour was not booked at midnight when we arrived. They managed to scramble to get us sorted out by the morning, but we were not impressed as it had been confirmed 3 weeks prior. They managed to obtain one set of tickets (not both) after telling us there would be no problem (this was halfway through day 1). The worst bit is the service fees - we were charged a fee (which wasn't indicated to us) for a service they could not even provide. This did not excite us. Pay pay pay.

Meals
We only ate breakfast at the hotel, which was reasonably priced by world standards, although once again, there was some confusion caused by our meal voucher. You'd think they'd handle this seemlessly in a hotel claiming to be 5-star. We didn't bother with other meals at the hotel after the concierge experiences and found very good restaurants located close by. We are big fans of fresh fruit and found the fruit presented to be quite tasteless.

Business Centre
Upon check-in, I was informed that I would be able to use the business centre at my leisure - there was no mention of cost. I was horrified, after using the Internet for approx an hour, to have a 200 peso charge awaiting me. The facilities are of a decent standard, but incredibly expensive.

Location
This is probably the best thing the hotel has going for it. The hotel is located in Polanco which is walking distance from Chapultepec Park (including the Museum of Anthropology, the zoo and the Castle) as well as many good restaurants. A taxi from the hotel to the airport is 260 pesos (why didn't concierge tell us this on the way in where we paid more with a booked transfer)?

Touring - not a reflection on the hotel, but worth a mention
We had booked tours (in addition to what concierge was supposed to book) that used Grayline as a local operator. Stay away! The airport transfer was overpriced and the tour didn't cover all the places it was supposed to (instead we got dumped at a souvenir trap for an hour so the guide could maximise his kickbacks). We were also told English would be the primary language for our tour, but we wound up being the only English speaking participants and suffered for that.

Other facilities
We didn't use other facilities of the hotel.

Overall
The hotel is clean and comfortable, but their add-on costs and efficiency of concierge are a big big turnoff. I would not recommend it and would not stay there again.

Mexico City: Hotel Nikko:"Beautiful Place"
I was afraid that being a business hotel we would be overlooked while on our vacation, was I wrong. The concierge service was the best i've experienced. They helped set up all our tours, and even set up our bus ride to our next city we were visiting. The rooms were nicely decorated and the beds were extremely comfortable. There are over five restaurants in the hotel and if you get tired of those the hotel Presidente is next door with more.
I would choose this hotel again.

I loved the Nikko. The service was incredible. It was a business trip, but I tacked an a couple of personal days onto the trip. It's a little pricey, and I normally would stay at a less expensive hotel for personal travel. However, I think the Nikko was worth it. I stayed on the executive floor, and found the room to be very comfortable. I read a couple of reviews about a hard bed, but I didn't have any trouble. With the executive floor you get free breakfast (quite good with cold and hot food) and free happy hour drinks/appetizers. The Nikko is the business district, Polanco, so it's a little farther away from the zocolo and the historic downtown area. But the touribus stops close to the hotel, and it takes you all around town (for about $10USD I think) and you can get on/off as much as you'd like. Prior to my trip, I emailed the concierge to arrange a tour of Teotihaucan/ Church of Our Lady Guadalupe. The tour was great, and it was very easy to arrange.

I was in Mexico City on business for the week of January 7 - 12, 2007 and everyday was great. Was upgraded to the Executive Floors and in a nutshell the only difference is your breakfast and drinks are included. There is some renovations being done currently on some Executive floors, but you don’t hear them at night.

OVERALL
Overall the hotel staff is excellent, always trying to lend a hand or offering to gather your bags. I did not see many tourists at this hotel, as I got the impression that it caters to the business traveler. Loved the idea that you can access wireless internet from anywhere in the hotel. This is great if you don't want to spend your evening in your room working.
FOOD
The breakfast buffet was my favorite since you can't go wrong with fruits and scrambled eggs. For dinner the Japanese restaurant on the second floor is the best. The service is great and the food is really good as well. There is a another Sushi type of restaurant on the main floor near the shops and I would not recommend it. The service was horrible and the waitress did not understand English. We got up and left after we asked for bottled water and couldn't understand what we wanted.
GYM
The gym and pool area are modern and the hotel has the latest cardio equipment. Word of advice, bring your own headphones if you want to watch TV as you do your cardio as people sweat and their sweat is left of the headsets....pretty disgusting.

Aside from that if I have to return to Mexico City, I would definitely return to this hotel.