I have a question for you veteran single travellers: I am booking a week in London in the Thistle Marble Arch. It's listed as deluxe. I am willing to share a room because I figure I won't be there most of the time and I can keep anything of value in a safe deposit box. Since it's deluxe, I figure there will be plenty of space, etc for two people to maneuver.

Other than my fears of a roommate who snores or is unclean or loud, what have your experiences been with this?

It will be my first time in Europe and I don't want to screw it up. Thanks.

Most european hotel rooms are much smaller than American hotels and Ireally wouldn't recommend it, often the twin beds are basically pushed together. I haven't shared a room via a tour but have been on Trafalgar and Insight tours and the rooms have been ok but normally small. Just my opinion.

Your (patvee) post made laugh outloud as I recalled a room we had (My 18yo Son & I) in Ireland that was so small we had to put the luggage on the beds so we could walk around and still could not pass each other without one of climbing on the bed. We managed and still had a good time, but it was SMALL. For the most part the places we stayed in England (London several places) were shall we say "Quaint", a bit on the small side compared to the ones in the United States which are about 1 1/2 times the size of the UK & Europe rooms.
Now the Thistle marble arch rooms are good size by london standards and you can go anywhere in London in minutes from there, so it is a good place to stay. I personally am fine with my family in the room, but dislike when I room with non family (even my friends) but thats just me. If it was me and the cost was small I would solo and I can guarnantee you will make friends in London you firsst night there, it is a very friendly and accesible city (my 2nd favorite city). . Enjoy hope this helps.