Does the length of the Sony NP-FH100 interfere with using the viewfinder for anyone? I made a shape of the same dimensions from stiff foam and put it in my HC9's battery case. By extending the viewfinder all the way out, I could get my eye up to it, but my nose was very snugly pushed against the battery-shape. Does this become annoying for extended shooting? It might actually increase steadiness, if it wasn't too uncomfortable. It would be better if the battery were about 6mm shallower or the viewfinder pulled out that much farther. I recommend to Sony that they make another model that is of that smaller depth and has about 3,000 mAh. The price at B&H of $100. (U.S.) for the NP-FH100, is the best I've found.

I have the FH100 for one reason - it's a nice counterweight if I've got a big WA and want to balance the camera for flying on a steady rig of some sort...

The FH70 (or a couple of them) is a better choice IMO for most purposes, and keeps the VF clear - the 100 rests on my cheek/nose as you've noted, not preferred, but usable.