The ultra clean fidelity of the DVDA does it for me, all the way! The new 5.1 mix is very nice too.
The DVDA could be accused of being a little dead-sounding in places, not quite as warm and analogue as the old quad and the background a little "too silent" but maybe that's being used to the hissy/noisy original!?
The DVDA could also do with a slight bass boost.. conversely the Doobie quads all have a bit too much bass, for me.
Also, not complaining as such, as its lovely to have it conveniently on a DVDR.. but the CD-4 transfer I've heard, while sounding nice in the main (and nice & discrete) suffers from too much speed-fluctuation type "wobble" that it hampers it a bit for me.