The Wharfedale Diamond 10.1 speakers won a Group Test in our previous, October issue - it was a very tight price-point test (all the contenders were £200-£250), so the B&Ws weren't included.
Others in the test were the Dali Lektor 1; Klipsch RB-10; MJ Acoustics Xeno XM1; Monitor Audio Bronze BR2; Mordaunt-Short Aviano 1
Yes, there are big differences, especially if you have a decent-sized room.
With home cinema amps of the quality/spec you're considering, the B&W 685 Theatre package would be a better fit than a package based on the Wharfedales.