Very close to the train station, but without any feel of "station" hotel: it is safe, well kept, with a rich decoration on reception and other public zones. But rooms are rather small, and window views, as expected, are not delightful. You have a kettle and free wifi in your room, which is nice. They have a vending machine instead of bar, but you still can buy some water or soft drinks.
Service is rather slow which is a bit crucial when you are in a _station_ hotel: you need to hurry up to catch your train sometimes. But a manager is really artistic, speaks a dozen of languages and is a star of the hotel.

A location is perfect if your have to depart early, but sure do not expect a respectable and quiet neighborhood. Still, it's quite safe and vivid and with lots of national cafes and restaurants (mainly Turkish, Pakistani and so). You have two big supermarkets just 5 steps away from the hotel. City center is 15-20 by foot from the hotel, or you can catch a bus. Shopping district is between a station area and city center.

Close to train station. The owner was fantastic, he kept a close eye on everything throughout the hotel to ensure the guest had a good stay. Large room perhaps a little dated but that's how we like it. Fairly quiet only noise we heard was from other guests talking in the corridor. Tea/coffee making facilities were provided in the room. About a 10 minute pleasant walk to the town centre. Bus to airport takes about 40mins costs €1.50 the nearest stop is close to the hotel just outside the station.

I stayed one night at this hotel. I opted not to book online with Hotels.com and instead used the telephone. Gianni at the other end was very helpful, confirmed the booking which he followed it up with an email and also stressed the fact that there is no need for advance payment or cancellation fee... rare these days. This saved me 10 Euro.
This small hotel is conveniently located near Place de la Gare. The bus from the airport stops just around the corner and costs only 1.50 euro.
I stayed in a twin room, which had a tv, safe deposit box, and tea/coffee facilities. Bed was comfortable enough, central heating was on and quite efficient even though it is a bit dated, which is also the case for the bathroom. I think the latter needs a facelift. I didn't particularly enjoy walking on the squeaky parquet floor without slippers which I forgot to pack, hence make sure you bring yours. I don't understand why many hotels do not provide them.
And there is free WiFI... although unsecured... now an expensive commodity in most hotels.
Breakfast was great, a good variety and plentiful; staff were very helpful and Gianni in particular is a charming hard working gentlemen. This is a hotel with genuine hospitality.
I recommend it if you need to stay a short time near the centre of Luxembourg.

I stayed at the Hotel Carlton one night with a EU court tour group consisting of lawyers, professors, and postgraduate law students. Apologies if this review is somewhat disjointed; it's late, but wanted to jot down some notes whilst they're still top of mind.

This is definitely a one-off place - not a chain - which has both pros and cons.

Its decor in the main rooms is charming and old-fashioned; decor in the individual rooms leans more toward 1970s neutral.

I don't want to sound like a snob, but IKEA branded mugs don't belong in a 4-star "heritage" hotel like this. There was a small in-room selection of teas, but no coffee.

At night, there were NO lights going down the stair way. Rather dangerous.

The elevator was slow and small, but this is Europe - so I'm happy there was an elevator at all.

The standup shower was of good water pressure, although the temperature did fluctuate. Toiletries consisted of an "all-in-one" shampoo and soap which smelled overpoweringly flowery. No hair conditioner. The shower also had one of those dreadful white, filmy, clingy, draw-closed plastic curtains. Thankfully, I am smaller so it didn't stick to me - however, it might do so to a larger person.

I appreciated the extra blankets. But an in-room fridge would have been nice. Also, there were no mirrors in the main area. Would have been useful for putting on makeup in the morning outside the steamy bathroom.

Bed was OK. Nothing great.

I normally walk around in slippers, but when I put my bare feet on the floor once, they picked up some dirt. Bare wood floors are difficult to keep clean, but still.

If you want any drinks from the vending machine after midnight, you apparently must call the front desk, who will then escort you to the 2nd floor to a wooden door marked "Bar". He stands there and waits for you as you choose your water, perrier, etc. It was kind of annoying as I wanted to take my time, but the front desk guy was just waiting there so I felt bad. Amusing touches are beer in the vending machine, and a standalone wine cork puller! The ice machine is also located in this room. When I called down from the second floor, he said there was an electric machine downstairs. So I went downstairs. We then went back up to the second floor. I wish he had just told me to wait on my floor at the elevator. Anyhow, just an annoying process.

The most frustrating thing was the breakfast timing. The night before, I asked the elderly gentleman what time breakfast started from. He said 5 and held up his hand showing five fingers. I asked him in both French and English. I thought this was early, but we were a tour group and had to be sharply out the door just past 7 - so was pleased.

I made my way downstairs at 5:45 to be greeted by another older fellow just apparently starting his shift (or coming from somewhere). He said it doesn't start until 7. I told him what happened (about timing), I asked for at least a bit of coffee. He very kindly quickly made me a small pot and poured me a small glass of orange juice to take back to my room - nice of him. Later on, before departure, I ate a croissant from the breakfast buffet. It seemed quite busy in there.

The in-room blow dryer is one of those machines with a hose attached to a wall, and the speed of air was very slow and weak. Disappointing. Hair dried a bit frizzy. Towels, waffle-like in texture, weren't very soft. But they were clean.

There wasn't much in the way of information, maps, internal information (ie- where the mysterious vending machine was, etc) in the room itself.

Free internet was useful and reliable.

All in all, it was an OK stay. Nothing fabulous. And in my opinion, closer to a 3 star than a 4 star.

Again, apologies for the scattered review. Hope it's helpful.