Just wanted to throw in a mention of Slate (https://github.com/jigish/slate) in here while we're talking about different options.
I've been a happy user for a while now. Haven't tried the others, though.
Love slate, switched to it after ShiftIt went unmaintained a few years back, though it looks like ShiftIt is back in active development. Slate config is really nice, you'll feel at home if you are used to setting up vim or tmux configs.
Slate is the polar opposite of Spectacle. It's too much configuration for most people I'd say. I couldn't get it to work, and get back to my actual work in less than an hour so it was a non-starter for me.