The expression above translate exactly what I feel about this hotel. There is a reason it is way cheaper than other Mercure hotels in London. It not feels like a Mercure at all. Would be more honestly if they re-brand it as Ibis.

But this not means it is a bad hotel. In fact it is quite good with comfy beds, nice shower with plenty of hot water, nice TV with premium channels and outstanding location.
The room I had stayed was quite big with a king size bed, good sized bathroom and bathtub. It was recently refurbished so the room itself felt like brand new but the bathroom have a tired look with some stains from the age but nothing that would bother me.
In the room you will find the usual: safe, ironing facilities, kettle, coffee and tea. In the bathroom toiletries as soap, shampoo, shower gel, etc.
Polite staff but not really proactive. But it is not a problem for me.

Location is superb. Close to Earls Court tube you can reach anywhere in London easily. Also if you are coming from Heatrow this tube station is part of Piccadilly Line. So you can travel from the airport terminals 1,2,3 and 5 to the hotel without change lines, what is very convenient.
Also not far you have the Gloucester Rd Tube and High Kensington St Tube besides several buses.

Speaking in High Kensington St, it is 10 min walk distance from hotel. Also It is a few stations away from Westfield London. So if your thing is shopping this is a good hotel to stay.
Yet related with location, nearby you will find a Sainsbury (one block away) and a Waitrose (more less 10 min walk) where you can buy groceries, sandwiches, etc. Also inside Sainsbury there is a Starbucks but I recommend the coffee from the Coffee Republic in the hotel lobby. it's way better than Starbucks and the price is right.

Nearby the hotel you also will find several restaurants of Thay, Indian, Italian and several other cousines and some pubs. I recommend the King's Head for pub. Nice atmosphere, nice prices and no attitude.

The brand Mercure may misleaded my expectations but it is in fact a good value for money in London. A huge downside is the charge of 20 pounds for 24 hours internet access. If you need internet don't buy it and maybe these chains stop to charge for something that should be part of the deal. Just go to a mobile phone store and buy a pay as you go SIM card. With 10 pounds I got a T-Mobile SIM with all the internet I needed in my mobile with possibility to use it in other devices.

I would recommend this hotel to friends.