Like many other big cities, London hotels are known to be expensive. The real problem, however, is that the price is not directly proportional to the hotel's quality. I have stayed in relatively expensive London hotels before that were below par and I have vowed to never make a similar mistake ever again.
The Arch is quite pricey - almost $3000HKD for a night's stay (if you book early). It is on Great Cumberland Place, slightly off Marble Arch and Oxford Street (around 3-5 minute walk from Marcle Arch tube station), which is fantastic, as you are only minutes away from all the shopping but silence is guaranteed. However, one point to bear in mind is that Marble Arch station is only served by the Central line, and its next station Bond Street (which has Jubilee Line connection) will be closed for upgrade from mid April to June 2014. So if you want a hotel that is near and within walking distance from the West End, you may need to consider somewhere else.
Basic standard rooms are not big but good enough; the bathroom is exquisite though. Large space, excellent amenities and a television in the shower.
Free minibar (bottled water, juice and milk) is a plus. A little comment on the wifi - it is slow. And reception can be almost to none in certain parts of the room (e.g. on my side of the bed).
On arrival we were greeted by wonderful and curteous frontdoor staff and bellboys; reception and concierge staff can use a bit more warmth though. Otherwise service was prompt. On our last morning we called frontdesk to ask for assistance with luggage and the bellboy came a bit late. A frontdoor staff came to us personally to apologise for the slight delay, which was a very thoughtful gesture. They were also very helpful in helping us locate our prebooked taxi to the airport.
Combining both price and value, The Arch did not let me down. One personal note to travellers - reviews are important. Don't just look at the overall rating but you really need to go into the details to know more about your hotel and destination. I must admit I am a bit obsessive-compulsive in this regard, but such trait has indeed led to well-made decisions for my vacations.