Well.... I went with a new RH450 which arrived yesterday; I coundn't justify the extra $300 plus I figure that if I want to get the RH750 it would be best to wait until they've been out for awhile to get a good deal on a used one. The RH450 sounds great to my ears but I did discover a mechanical problem with the headphone jack... it does not work nor does it cut the sound off to the speakers. I've contacted the dealer and they've emailed TC Support so we'll see what happens next.