Metacity do no seem to provide any non opaque modes 
for moving and resizing windows. It is also not possible
to disable the animations (for instance while minimizing). 

All those features consume a lot of computing power and 
network banwidth. 

I am currently setting up a Linux login server which 
may have to run more than 30 desktop (gnome2 or others). 
The user are running the Exceed X11 client on their 
Win2000 pc. You can understand that our policy is to
avoid all cpu intensive tasks on the login servers (we 
have compute servers for that). From my experience, 
an opaque move usually consumes from 5% to 40% of the 
cpu depending of the context. This is far too much for 
such candy eyes features. 

All other wm I know provide a 'wireframe' mode.