Make sure that if you do listen to some B&W 685's that they have already been run-in and they are on very good speaker stands which are mass loaded.
When i auditioned the 685's with my Arcam Alpha 9 amp and CDP and with my mates NAD C352 (before he gt the C355) we listened to 2 sets of 685's, one new and one set with 100hours usage & both on Atacama SE20 stands loaded with 7.5kg of atabites in each (we changed each stand weight between 4kg and 8kg and found that 7.5kg was bang on for the room we were in, fussy i know haha)
The difference was chalk and cheese!!!
The run-in 685's with the C352 sounded fantastic. We listened a low volume and they did sound a little light but then when the volume was at about 9 o'clock, they came to life all the way up to 11 o'clock. Between 10 and 11 o'clock they were awsome. The power was unbelievable and they made his B&W 603 S2's sound naff!!! The bass was deep and sublime, treble was crisp and the midrange timing was spot on. They sapped up the NADs power and spat it out with avengance!
The new 685's were bloody awful, but to be honest we kinda expected that. They sounded hollow and lifeless until they were turned up fairly loud, which isnt a good idea with new speakers.
If your budget can stretch, i know youll like the 684's as well! I'd also say try auditioning the RS6's and RS8's too. You'll be surprised how good they sound with the NAD C355. I was!!!