I'm running 501's with Micro Be's (w/ Revel Sub30) and absolutely love the combination. Overall, a very liquid and transparent sound without being analytical or "hyper" detailed. Along with an incredible sense of the recorded space there is an organic flow to things that draws the listener in. Of all the set-ups I've had over the years (there have been many) this has been by far the most rewarding musically. Gone are the days of listening to just one track on a CD if you know what I mean. Is it really 3am? ;-)
Happy Listening!
Happy Listening!