This week's book giveaway is in the Mac OS forum. We're giving away four copies of a choice of "Take Control of Upgrading to Yosemite" or "Take Control of Automating Your Mac" and have Joe Kissell on-line! See this thread for details.
Just search this forum - there's plenty of discussions about this. Take them all with a pinch of salt where the say "A is better than B" without giving a reason (but I'm sure you'd do that anyway). People have listed plently of features they like so maybe you can get an idea.