What's the point of having one on a portable unit? My whole home audio system is connected through SPDIF but I couldn't think of a sensible use for it on the road.
Ralf
Their are alot of people that use external Pre's and AD's to use SPDIF. Or someone may want to have a backup recorder attached digitally. People have done this for years (since the early 1980's when the first PCM setups become available - where the AD and recorder where different pieces of hardware)
Zoom's are not aimed at the professional market (only the semi-pro, hobbiest, etc) so I can never see them adding this feature. They offer recorders to staple to your camera to get moderately better sound then you will get out of the camera internal mic.
I think the only reason Sony and Tascam offer digi in's on there midrange handhelds is because they have offered this in the past.
True bit buckets are all but dead as their just isn't a big enough market any more. How many videographers do you see lugging around a V3 or even mixpre-d around with there DSLR setup.
Maybe if camera makers start offering digital in's with 24bit bit perfect recording a rebirth of external AD's and thus bit buckets will hit again.