I'm gonna have to go with the hammer type style pommel.
I think they'll both do well at breaking glass, but When I think of what I would use the pommel of the knife for it's hammering things that I don't necessarily want to break into place (computer cases, desk draws etc), or hammering -onto- it with another object like a log, hammer, rock, or whatever's available (probably a boot around the house) to get it to go deeper into something for pyring (pallets). for that, the skull crusher pommel is way more likely to mess up what your hammering it with, and won't get as good of a contact/force transfer from the hammering motion. you'll have to hit harder and more often on the skull crusher to get it to go in.
your also less likely to sheer the scales out of place with the hammer time pommel. I'm way more likely go get a solid hammer grade blow straight into scales (parallel with the tang) on the skull crusher then the hammer time, something that with enough hits will end up distorting/sheering the tube fasteners.
I know having a hammer time pommel and no choil makes it all kindsa uncool looking, but MAN will that blade be packed full of functionality.