I actually find that I have trouble with the rau used in Dalu/Nokama Metru, because the downward-pokey things on the bottom always restrict poseability, and usually when the mask is used I end up with a similar styled build- a slim/agile body
Hmmm, I get what you mean, that old grey is a bit of a yucky colour (probably why they changed it). That being said, there are still several usable parts available in the same matching old dark grey (mostly from the Rahkshi).
I actually recently used it a MOC (though to be fair, it was an Ehrye revamp). I can totally understand how it’s hard to use. Those weird wires don’t really have analogues on other BIONICLE parts.
One ‘mask’ I find everyone complaining about is the Gadunka mask. I don’t know what’s so hard about it, I find uses for it all the time. If I had more I could make some really incredible stuff.
Yeah, I’m guessing people find that the carapace/shellfish-style textures it has only really work with a very limited number of other parts released in '07. What’s more, that mask only comes in a weird trans-blue/marbled glow-in-the-dark colour (also only really seen in a few sets in 07).