I think the thing that bugs me about those icons is that you're using squares to represent things that don't really make sense as squares. These look smaller and sleeker, and as I said there is definitely a place for them, but I really feel like a compact view option would be nicer to work with.
It's probably more of something you want to think about once you get everything up and running, though. As long as you don't do anything silly like hard-code square icons in
