From: Rod

I have taken on board the understanding that the A/D specification is
an indicator of the *potential* Dmax of a scanner given the CCD is
good enough to supply sufficient data to the ADC. No makers ever seem
to give an actual measured Dmax, they just give 12/14/16bit x 3 as an
indicator of potential dynamic range. Apart from trying several
scanners for myself and also taking price as a sort of indicator of
CCD quality, how do I know which scanners are going to make the best
of my slides?

Best to either try out the best models (hard to do) or see if someone will do
sample scans for you (I've done that a few times for people I know) or look at
samples of the same image scanned with different scanners, like here ...
nothing like looking at actual files to help you make up your mind.
http://www.imaging-resource.com/SCAN1.HTM

An obvious problem is going to be my habit of trying to
take pics when the brightness range is way too great to get good
highlight and shadow detail on the film, let alone on on a scan.

If the film won't hold the dynamic range then it just gets worse when you scan.

I see some good close out deals on the Minolta scan multi II. How
much difference would I see in A3 prints for the 12 bit A/D compared
with the 16 bit A/D of the Scan multi pro or the 14 bit of the
Microtek Artixscan 120TF?

Probably none in real life, assuming the color rendition was similar and the
rez was similar (I think the Artisan is a 4,000 dpi scanner, the Minolta is
3,200 x 4,800 so you have to resample to get the same or higher rez).

Looking for scans at least comparable
with those I'm getting from 35mm on the Nikon Super Coolscan 4000ED.

Look at the Nikon 8000 or 9000 too then, since you'll already be familiar with
the software. Many people (me included) would choose the Nikon over either the
Minolta Multi or the Artisan (which is a re-branded Polaroid).

Bill