I am currently doing a home listening test with the Monitor Audio GR20's. Last weekend I compared them with the B&W 704's and Spendor S6E's. Whilst I am 90% decided to go with the GR20's I am mindful that they have been around for about 4 years now. Should this be a concern? Does anybody out there have any inside information as to possible replacements or changes to the current model?