I thought the M&V exchange in Berwick Street (that's Soho I guess?) wasn't very good... I spent well over an hour browsing all the racks (because it was the only on that was open early on Sunday morning
) and there was hardly much of interest to me.
Reckless seemed to have a pretty good stock for a secondhand store, but a bit lacking in the avantgarde/improv section... lots of indie rock. Didn't get to see the dance store down the road.
I thought the new Sister Ray/old Selectadisc was still pretty good, better than most of the shops I get to see back in Holland. I did go to the old Sister Ray and Selectadisc 2.5 years ago (around the previous ATP) but I don't remember enough of those in order to compare, except that the old Sister Ray wasn't that good.
Rough Trade in wherever it was that T&B took me (Camden?) was alright, but not amazing. Sounds of the Universe looked interesting from the outside, but it was closed the first time and the second time there wasn't really enough time to go there and I really wanted to see the Rough Trade shop too.
Back in 2004 it was a bit of an eye opener for me to see that the difference with the average London stores and the Dutch ones I know in Rotterdam/Amsterdam/Utrecht/etc was smaller than I had imagined it to be. Of course London has much more stores and therefore gives you a better chance of finding what you're looking for, but when you compare stores individually then there was some difference but not an awful lot... meaning you still have to spend lots of time wondering about many different stores for a lot of obscure stuff, in the same way like I have to do here. That may sound ridiculously obvious, but I had this naive image in my head of finding the perfect record shop where you can just spend hours on end looking for everything in each genre that interests you... well maybe there's a place like that in NYC or Tokyo. Berwick Street as a whole is probably the best place for record shopping I've been though.