Quote - The thing is, I need to see how every single vertex moves when I go between 0 and 1 on the dial, then fine-tune the morph vertex by vertex until it's exactly right. If Poser can't do that, I need to find a tool that can, and doesn't burn a huge hole in my bank account (not to mention a steep learning curve). I have to say, I was never that impressed with Poser in terms of its interface and usability. So unless someone tells me that the new vertex brush is the bee's knees, I guess I won't even bother trying it.

The question then becomes: do these things work well enough in Blender to be worth the effort of wrapping my head around its palimpsest of chaotic widgets and idiosyncratic, undocumented hotkeys, or should I just spend the extra time and write my own tool which will do exactly what I want the way I want it? I have to admit, I'm starting to lean a bit toward the latter.

Hi OFD
Blender does work well for precise morphing. From my experience ( which isn't much just the bare basics ). It may be worth a try to learn atleast the following things.

A. Selecting vertices in edit mode and moving them on a fixed axis. Right Click verts then use G-key to grab and press X,Y or Z to move verts along that axis. Left click to confirm. You can even create vertex groups for easy re-selection.
B. Sculpt mode
There quite a few tools here but there really simple to learn in a day. Symmetry with Lock Axis X,Y or Z is awesome for sculpting along a fixed axis for more accurate sculpting.
C.ShapeKeys
This kind of works like poser dials where you can dial values and mix morphs. You can animate them with the timeline to see how they blend. There is alot to learn with how shape keys work but the blender site has a good wiki article all about it and it took me a few days to get the basics down.

Note: I do not recommend to use Multi-Res>Catmill Clark option when sculpting. This option has given me problems in the past ( moving verts I never sculpted on ) even when bringing it back to it's original level. I think it's bugged. Instead you can use add modifier>Subsurf to see details while sculpting.

I can't guarantee you'll love Blender in a few months but just give the three things I mentioned a try and I think you'll find them very useful. As Joe suggested, practice is your greatest teacher.