I cannot make up my mind. Would appreciate feedback from fellow Pro owners. Here's my current set up - 1. 13" MacBook Air, 2010, 4gb ram, 256ssd. It is my 'main machine' because I'm often using my computer away from my desk. It's lightweight a pleasure to use and handles my work fine. 2. 17" MBP, 2011. It's currently sitting on my desk hooked up to an ACD. When I'm at my desk I use the 17" for design work, anything that benefits from the larger screen, my Air sits on the desk as well for mail/calendar monitoring etc. I like and bought the 17" because I didn't like having my Air leashed to an ACD, I'd plug/unplug it too frequently, and I'd liked having the option of being able to detach the 17" from the ACD and still have the large mobile 17" display for work away from my desk. 3. 2009 Mac Pro Quad. I don't use it often but it works well as a server, back up, downloading, always on machine. It's important for us to have an always on machine of some sort. Since I bought the 17" MBP the Mac Pro gets used even less than it was before. Yet the Pro still serves a purpose and if I sold it to warrant keeping the 17" I'd loose my 'always on machine' if I decided to take my Air and 17" with me. Money isn't a concern, too many computers is. Can I use three machines, for one thing or another certainly I can. Maybe I'm just feeling a little buyers remorse on the 17" and guilty for having so many machines. The reason I'm second guessing is that I use my Air 80% of the time. What to do? Suggestions please.