We've been at Fleming's for a week in New Year's Eve. We got a really good fare that included free minibar, robes and slippers and free Pay-tv (only adult content, though).
Overall, the hotel is better than we hoped and I'd recommend it.
Location : close to main train station (300 m), a tram stop (Platz der Republik) around the corner with 4 lines (line 11 get you to downtown). Cafes & pubs nearby and plenty of fast food in the railway station. It's a safe area although you can watch weird people at late night.
Rooms : quite big (250 m2), large and comfortable double bed. Wide range of tv stations. Enough closet space for two. About the famous glass walled shower, it's really good and fun!. But only if you travel as a couple ,I guess.
Staff : Room cleaning is very good and staff is polite and helpful. We asked one more blanket and to heat up the room and they complied at once.

So if you're looking for a nice hotel with a short budget this is a good choice.

This is a very well located, stylish hotel. My ground-floor single was roomy and had an ultra-modern decor. The room was all white with dark brown furnishings. The bathroom basin was of frosted glass. The bathroom arrangement was fronted with glass and had no door. You could look directly from the bedroom area through the glass into the shower stall and bathroom counter area. The room had a low profile bed, closet, safe and roomy bathroom granite counter.

The hotel is an easy 2-block walk directly north of the main train station. Most of its ground-floor public area is taken up with the hotel's restaurant. The lobby consists of just a long registration desk located in a small room.

This hotel is in a prime city location. We were able to walk around during the day and evening and felt safe. It is surrounded by office buildings and some other hotels. We had a room on the 3rd floor that faced the street. The noise was not too bad...until the police or an ambulance came by...then it was really bad. The room and lobby appear very modern. We chose to drive in Germany and drove from the airport. Parking is sparce. The hotel has about 10 spots and that's it. To enter for parking, you need to enter the driveway in front of a rollup door, ring a doorbell and find a space either at that level or via a car elevator in the basement which is very tight to maneuver in. The hotel has a gym in the basement with 3 or so machines which seems rather useless. They also have a decent sized sauna and a steam room that seats 2 very intimately. The hotel restaurant was pretty good. We ate breakfast there which included eggs to order and other european pastries and deli meats. We ate dinner there once too. It also was prepared well, good service and priced decent for what we got. Overall I would stay here again if I had business in Frankfurt. However, as a tourist, I would look a little harder next time. The front desk staff were courteous and did what they could to understand english. One word of note...don't get driving directions from them. Ask for a map and do it yourself. The hotel is close to the train station and that was convienent too. The room was fairly modern with a glass bathroom, low bed, small desk and decent television. Housekeeping did a good job. The A/C wasn't as powerful or as cold as what I'm used to while traveling in the US but it kept it comfortable. We had a regular room that was $161.00 euro per night. Again...not bad but next time I think I would look into the Sofitel which is on a quiet street 2 blocks away.

My wife & I staying in Flemming's Hotel Frankfurt Messes for 4 nights, the staffs are nice and helpful. We're living on 5th Floor (highest floor), street view, facing commerical buildings but in a distance, sun-ray is enough, just very little traffic noise could be heard when all windows being closed, but no worry, the room have good air-conditioner, that's not a problem for letting the windows being closed. Room is clean and have enough spacious for luggages. Open shower box and basin design is modern.

As our package is exculding breakfast, we're not sure the 15 euro breakfast in there is value for money or not. However, we've tried 2 nights dinner in there, we're soooo impressive the tasty Onion Soup & Tuna Steak from there.

We're Hong Kong people and we used to drink a chinese tea at night (good for disgestion), but the room didn't provide the kettle, means we need to take 2 cups of hot water from the bar everynight. And maybe it's my laptop's setting problem, i've connected to their free wireless LAN, however, never succeed to load any pages.

Sure we'll stay at Flemming's Hotel again next time.
We've a happy experience in there. Thanks again for their profession services!