I'd be real careful here - Quicken is not made to do this. Definitely play around with a "test" version for a while.
I use the Windoze version and tried it once with that. It appeared to work, but after a while I started to notice little things like reminders not clearing on both machines. Turns out even though I had the data files on a server, each PC was also putting stuff in a local directory. Now I don't know if the Mac version handles files the same way so have no idea if this applies; just be forewarned.
Turns out - at least on Quicken/Windoze - the only way to "share" the data file is to do a backup/restore. That is, backup every time you shut down (to some shared location), then restore every time you start. Really not a big deal, and it works. Same thing if you wanted to move data from desktop to laptop when you go on the road.