I also will be interested in the replies you receive. I've probably heard the B&W 803 speakers, but don't recall them. I do recall being very impressed by the Merlin TSM speakers, and being amazed by the sound from such a small box.
I heard the 803's with some Rotel and Wyred for Sound amps and didn't like them...very etched and bright and the midrange was all wrong. Later I heard them again with Cary amps and pre and thought they were VERY good and almost sweet sounding. But they still sounded like boxes to me.
I started reading about the Merlins and heard a pair of TSM-MMe's and that was that. They are amazing....so much so that I have a pair of the latest versions from Bobby. I've already bought the Manley Stingray II amp to go with them.
I listened to a LOT of speakers before taking the leap. The Merlins have a cult-like fan base for a reason. I'll be posting a very complete review of the Merlins when I get them, but yes....I do prefer them over the 803's and the Revel M22's (which I nearly bought) and the Focal Utopias among others.