Sonics: Marantz vs Denon AVRs "Pure Direct" mode

Just curious...does this mode have any significant fidelity improvement? Also, in 2 channel mode, can one take advantage of a sub? I heard that all bass management capabilities is disengaged when using this feature? True? Denon the same?
I own an Onkyo pre-pro and have extensively auditioned the Integra version of same. In both cases, the flip to "direct mode" yielded a subtle but audible difference. I suspect that most folks here would prefer it but for me it was too close to call.

I use mainly Ohm 100s with Rythmik subs. When I listen to LP (rare these days) I tend to go direct (habit, as much as anything) and lose the subs. The Ohms have enough bottom end to make this worthwhile, especially since almost all of my LP time is spent with acoustic, small scale recordings with limited deep bass and macrodynamics, anyway. It sounds different than the room corrected, subwoofer supported digital listening that I mostly do and it's fun to slide into old school audiophile mode from time to time.

However, I'd never choose to use the subs without the DSP engaged, as I cannot abide subwoofers that aren't precisely integrated these days and I can't get satisfactory integration without the help of the DSP (although its possible that others can).

At the end of the day, I went 99% digital because Audyssey allows full range, room corrected sound that I find very satisfying and because my music server puts every digital recording that I own on a touch screen. I have a very high quality analog set-up, but -to be honest - it doesn't get a ton of use these days. I guess I've gone to the dark side.

Just one data point for you
One more point:

If there's any meaningful bass in the recording - analog or digital - it will ALWAYS sound better with the DSP engaged. And IMHO, not by a little.
I've never owned AVRs from either company, but I recently upgraded out of a Marantz integrated amp (PM8004) so I can comment on the Pure Direct mode on that component. And I also own an Onkyo AVR with that feature.

On the Onkyo I cannot hear any difference whatsoever with that feature engaged. Doesn't matter what kind of source material, I just can't hear any difference. For all I know, the button has been broken since I got the thing :-)

The Marantz is a completely different story - the Pure Direct on that makes a big difference to the sound. It made the sound much more airy and live-sounding, with greater presence, sparkle and depth. On darker recordings, or live performances, it was really nice. Of course, on brighter recordings it made things worse, so I had to be judicious in using that feature.