QTR-Quadtone RIP

That's the title of a short paper by Paul Roark in January 2006.  He
seemed fairly satisfied with the quality of the QTR profiles that he
was making with an Epson Expression 1600 flat-bed scanner (in lieu of
a densitometer or spectrophotometer).

I'm considering going the same way... but with an Epson 1680, which
can still be acquired new (unlike the 1600).  What do you folks think?
 Is this likely to be satisfactory?  Are any of you happy using
scanners... or are you convinced that a densitometer is the only way
to go?