Hi Alex,
Thank you, and yes it is totally different. I have about 70 hours on it since posting. I am running it constantly and listening in between to get at least 100 hours on it before listening more critically. The first thing noticed is the authority of the notes, they are more dynamic and with greater presence on recordings. Midrange seems a bit more natural, from what I have read from it's reviews the Ref 10 is less "tubey" in that region compared to the Ref 5SE allowing the music to be reproduced more naturally. The soundstaging is much wider (separate power supply helps) and on the right disc the music seems to coming from almost outside the speaker's boundaries. I'm waiting for the three dimensional soundstaging to take effect. I clearly remember my Ref 5SE taking time to open up, IIRC it took at least 200 hours before it settled in. Really enjoying the ride so far.