Moth3r, I would be very interested in having the comparison track, both for its own sake and to determine if there is anything that I need to re-edit for my version. By all means please upload it! :) It's strange how they bothered to mix in something so minor as that water noise when legitimately improved effects such as the mono mix "deceleration" sound when the Falcon comes out of lightspeed are nowhere to be found in the '93.
msycamore: Actually, those scenes weren't all that difficult. It was only a matter of finding appropriate places to switch--conveniently located sound effects help disguise the transitions. The dynamics obviously do not reach the levels that they should in the cell bay shootout, but it still sounds good--vastly preferable to those ridiculously loud shattering glass sounds.
I will certainly be uploading the stereo version for anyone who wants it. I'll most likely save it as a FLAC file and then split it into a few RARs to make the uploading easier, which can then be used as a PCM or high-bitrate AC3 track, whichever is preferred. This method may yield slightly greater fidelity than what can be had from upmixed 5.1, and would be ideal for those without a surround setup available.
The 5.1 version would be best for those with surround setups, in order to take advantage of the extra bass content. This is the only real reason to do the upmixing on the computer, since non-standard formats like 2.1 are problematic and the playback results are entirely receiver-dependent. The bass was an important part of the 70mm theatrical experience, and I would recommend that it be heard this way if possible.
It should be noted that downmixing a previously upmixed surround track back into stereo is not ideal, because the surrounds may have a 20 millisecond delay added to them, which could cause phase issues if combined back with the main channels. The six-track original wouldn't have this issue, of course, since its mono surround channel would contain discrete effects only. Upmix results won't be precisely the same--the matrixed surround cues emanate from both rear speakers as they should, but there is also additional stereo ambience derived from the left and right front channels (as well as a bit of unavoidable crosstalk, although much less with modern algorithms than with the original Prologic).