Hi theguz.

I use VNAV all the way down. If there are altitude or speed constraints, I find that the 757 obeys them when using VNAV. The ones that create the problems (if at all) are the altitude constraints that have, for example, 17000A at the end of them (be at 17000 or Above at the waypoint. So why don't you let VNAV control the descent?

I have found that it is more likely to exceed an altitude constraint during the climb phase than during the descent phase.

Mark