The longer I do this, the more and more I find it time consuming to work on P2P. Having to maintain users accounts, backups, programs, etc. on each individual workstation one at a time can get annoying, especially remotely. Actually had to work with a practice who had 17 computers. Each one with 3-4 different user accounts with different passwords. Now they have Active Directory with folder redirection and centralized backup of all 17 computers. Makes my job a lot easier as well documenting a backup plan. SBS/Server 2012 Essentials is truly quite amazing. You can have full image backups of each and every computer on the LAN. Also, the folder redirection allows a simple file backup of all the files on people's desktops, documents, favorites, etc. With that kind of system, you only need to spend an hour or two a month to maintain the system.

The better the initial setup is the less work has to be done in the long run. Almost all of my setups are self-maintaining as well. I just read the report every now and then to make sure things are going as planned. However, if you're planning on doing your own IT, P2P is probably better for you. If you want someone from the outside, it's better to use Active Directory.