Thanks to this thread, I was convinced to buy an XDRF last week. Got mine from Compusource.com for $84 shipped. The receiver arrived in two days.
I connected it to a Magnum Dynalab ST-2 Omnidirectional antenna mounted in my attic. Maybe I'm under the "influence" of the positive reviews here and elsewhere, but I think the FM audio quality on this tuner sounds just about as good as any FM tuner I've had in this system, including a McIntosh MR-80 and my current Magnum-Dynalab FT-101 Etude. I say "just about" because the XDRF sounds a little hard, bright or "edgy" in the mid treble range by compairson to the analog signal through the Etude on some stations when it switches to digital mode. But it's hard to say whether that's the fault of the tuner or the broadcaster. It would be nice if this had an "analog only" control for A-B comparison to analog tuners on all stations. On analog only stations, the differences between it and the Etude were really, really difficult to discern and -- when I could hear a difference -- it was hard to say which was more objectively accurate or even more subjectively preferable. I could easily live with the XDRF except I'd miss fiddling with all the switches and controls that are available on the Etude.
I live in a radio-rich urban environment where there are plenty of strong signals available, so I can't really comment on DX reception abilities. It does seem to do a great job of rejecting nearby frequencies, however, and multipath seems to be a non-issue. It picks up without fuss stations that I have to use the "narrow" selectivity option to get cleanly on the Etude.
I wasn't as impressed with the sonic qualities of the AM section. My current AM tuner is the AM section of an NEC T-601E. The NEC bests the XDRF in AM sound quality. The XDRF sounds as if the midrange is much more emphasized than the rest of the frequency spectrum by comparison to the NEC. Even with the XDRF in AM HD mode, the NEC sounded better in an A-B comparison. AM HD, on the few stations in the Dallas area that offer it, sounds phase shifted, kind of like a low bitrate MP3. However, AM is AM, after all, so I'm not going to knock the XDRF too much for AM sound quality. Without the A-B comparison, I wouldn't have found the AM sound quality of the XDRF unbearable or even objectionable.
Beyond the sound qualities of the XDRF is the additional content. I was delighted with a couple of the sub-stations that I was able to pick up in digital mode. Overall, this has to be the best sub $100 purchase for a new peice of audio gear that I've made in a long, long time. The whole experience has re-kindled my interest in FM and in trying out some of the new stations that I can now pick up. Thank you to those who helped get out the good word on the XDRF. I guess the next step is to get another and look in to some of the mods that are floating around for this little gem. Anyone have any first-hand experiences with those?