The following link may be of interest:
http://www.flightsafety.org/cfit.html
The CFIT working group concluded (i) that constant descent profiles are significantly safer and (ii) that we must add an increment to minima to allow for sink.
There are lots of ways of achieving a good profile, including groundspeed and time, DME ranges and FIX page information, FPA/FPV for those lucky enough to have it, and last but not least, good flying!
We fly EFIS jets, and never have problems flying these profiles to hit each altitude to an accuracy of +/- 100ft at worst. Usually accuracy gets betterthe further down the approach, and I have never seen anyone reach MDA not in a safe place to land normally.
The working group gives its advice in good heart, in the hopes of saving lives which CFIT might otherwise have claimed.
ManagedNav and BEagle, have you tried flying constant descent profiles? If you have and it didn't work out, I wonder why.... If not, give it a go. I was initially sceptical, but it feels much, much, safer now, and I wouldn't fly level to VDP ever again.