I know you really had bad experiences with RSX vertex shaders but I can assure you that properly used they do their job very well, it's extremely difficult (if you are clever enough..) to be vertex shaders limited.
Thanks for the candid answers nAo! I think our differences regarding vertex processing are because we're dealing with very different numbers in very different situations. I'll give you a simple example that actually just happened today. We're shooting for 60fps, and one of our test views mysteriously dropped to 47fps today. Long story short, there was a bug and we were drawing thousands of 3d crowd at their best lod. Pix reported crowd alone being ~4.2 million verticies. Add in our players (which thanks to PS3Devcon I now know are > 10x times the geometric density of our PS3 competitor) the stadium, etc, and you can imagine what type of vertex count we're dealing with! One big thing we have to deal with is replay with a free roaming camera, where everything gets examined in excruciating detail. This forces us to raise the bar substantially.