I agree - a 2+2 needs to be symmetrical and it needs to have a reasonable size to it
here's a few images to get the discussion going
I like the overall feel of an Alembic headstock, but the top end is a little too large for my taste. I realize that they do this so that the same headstock easily accommodates a 4, 5, and 6-string configuration
Spector has a decent 'generic' shape, but it isn't something I ever remember (and often have to look elsewhere to recognize the brand)
Zon's are another decent headstock for size and side shape, but I don't really care for the blockiness on the end
I was hoping to find a Smith 4-string headstock, but I struck out so far
I like this headstock in the 4-string flavor, but definitely not in a 6er
so shoot away at what you like/dislike on these - and feel welcome to add images of headstock that have the "it" factor pegged
all the best,
R