Firstly you have great speakers so if you never ever changed I would understand as that would probably be the most sensible thing to do. As others have said you are changing for teh sake of changing. However, perhaps you have the 7 year itch.
What can I say about the B&W 800d's if I were to nit pick.
1) They are bass extended with a port at 40 Hz (this will not be quite as tight as a sealed box or a pro design that uses a port for higher efficiency or a subwoofer without port for the bottom octave) On the upside you get fantastic powerful bass - probably ideal for HT - but it may cloud or muddy the lower midrange except in large rooms.
2) The B&W midrange is exceptional - but it has one weakness - it is too large for a midrange and it beams. Therefore you get a weak presentation off axis from about 1 Khz to 3 Khz with most B&W's of this type and the 800d is no exception. When the dome tweeter kicks in around 4 Khz you suddenly get a proper presentation (wide dispersion off axis) and this tends to make for a relative sudden boost at these frequencies (remember you hear the primary direct and the off axis reflected signal which are combined to give an overal audio presentation to your brain - so things will jump out at you a bit more than they should - and this helps sell as it dinstinguishes B&W's and gives them their "detailed" but polite sound). In essence this type design is called the classic "BBC Dip" and although a coloration it is EXTREMELY popular - it is associated with a warm and less harsh sound - seeing as it is used in many of the most susccesful speakers on the planet - again not a real issue and if you like classical this is a great presentation!
Nothing to worry about. The above is in the category of extreme nit picking. (looking for faults when there really aren't any - as this is B&W's best speaker by far)
What can I say about the B&W 800d's if I were to nit pick.
1) They are bass extended with a port at 40 Hz (this will not be quite as tight as a sealed box or a pro design that uses a port for higher efficiency or a subwoofer without port for the bottom octave) On the upside you get fantastic powerful bass - probably ideal for HT - but it may cloud or muddy the lower midrange except in large rooms.
2) The B&W midrange is exceptional - but it has one weakness - it is too large for a midrange and it beams. Therefore you get a weak presentation off axis from about 1 Khz to 3 Khz with most B&W's of this type and the 800d is no exception. When the dome tweeter kicks in around 4 Khz you suddenly get a proper presentation (wide dispersion off axis) and this tends to make for a relative sudden boost at these frequencies (remember you hear the primary direct and the off axis reflected signal which are combined to give an overal audio presentation to your brain - so things will jump out at you a bit more than they should - and this helps sell as it dinstinguishes B&W's and gives them their "detailed" but polite sound). In essence this type design is called the classic "BBC Dip" and although a coloration it is EXTREMELY popular - it is associated with a warm and less harsh sound - seeing as it is used in many of the most susccesful speakers on the planet - again not a real issue and if you like classical this is a great presentation!
Nothing to worry about. The above is in the category of extreme nit picking. (looking for faults when there really aren't any - as this is B&W's best speaker by far)