I am in London and thanks to a recommendation from Ked, found myself tonight at an LSO concert at Barbican Hall, which is a nice warm-sounding hall. (Ked probably likes it because the entire back-stage wall looks like it was designed by Shun Mook!) I heard Sibelius' 5th (not my cup of tea) and some god awful premier of a modern commissioned work. But the gem was the Elgar Cello Concerto performed spectacularly by a German cellist named Daniel Mueller-Schott. He had it all, superb technique, emotion and intellect. It was the best I ever heard that piece performed live.
The Elgar is a great concerto! We heard Steven Isserlis play it at the Barbican with the LSO a few years ago.
We're off to London next month. Mueller-Schott recorded the Brahms Double Concerto with Julia Fischer on Pentatone on SACD. I very much enjoyed the recording (which I listened to in mch). I think the Barbican gets dissed a bit too much, especially if you are sitting somewhere in the middle stalls. However it probably is a moot point, since I believe the deal to get Simon Rattle back to the LSO is to also build a new concert hall for him to replace the Barbican (I think closer to the tube station.)
There are many fine halls in Europe. The most famous large halls are the Musikverein Grosser Saal in Vienna and the Concertgebouw in Amsterdam, often considered two of the three best halls in the world (along with Symphony Hall in Boston). We really like Wigmore Hall in London which is great for chamber music. Seats don't have enough leg room for me, however. Smaller halls are easier to have great acoustics. There are many smaller opera houses through Europe which are also fine. I remember two in Prague, one of which I think was used in the Amadeus movie. We like Glyndebourne south of London.
BTW, halls that are great for concerts are often not so good for recording. Decca used a different hall (Sofiensaal - an old dance hall) for their Vienna Philharmonic recordings in Vienna.
Larry