SmartSync has a deceptively simple premise; it keeps two directories in sync with each other, pretty much wherever they are. It functions like this, you give it a source, destination, schedule, and method, and forget about it. It then works unobtrusively in the background, keeping your files the way you want them. The magic is in the flexibility.
You can keep two directories in sync, but how you do it is rather impressive. It works from drive to drive, over network shares, FTP, removable media (Zips, CD-RW with appropriate software), and probably other things I didn't have time to discover. You more or less tell it where to move the files, and it can, one way or another. The only thing that would make it better is a 3rd party based relay center for people with 2 machines, each behind a NATed firewall. While this is an option for monthly services like GoToMyPC.com, it is a little much to ask for a $35 utility.
After you give it a source, destination, and method, you can then set filters, letting you do things like only syncing .Doc files, .MP3s, or, conversely not copying a certain file type or four. I ran out of ideas before I ran out of abilities to filter things, but I assume there are limits.
After that, you can set it to run automatically, manually, or the best one, whenever there are changes. If you set it to run on startup and shutdown, you will make sure every session is essentially backed up to another machine, or another HD. It almost makes things too easy. If you have to go back and forth between many machines, you can make multiple entries, called profiles, and have them all run.
After a few of these profiles are created, things can get complicated, but no fears, there are some fairly extensive logging features built in, along with a simple but curious omission. The good parts of the logging are that is shows start, stop, and bytes transferred. It also has a separate window to show things changed in the directory since the last update. This is ungodly useful if you have to sync a large directory over a slow link. The bad part is that it does not show the individual files synced, which can be handy if you are troubleshooting. A logging level feature would be a useful addition.
In all my attempts to sync weird things across my network, I couldn't get it to fail, so I can't actually tell you how it handles errors and unexpected situations. I have been running it for over a week, and it exhibited no unruly behavior or conflicts with anything on my system, a very good sign. It sits unobtrusively in my system tray, doing its thing quietly.
If you have a small peer to peer network that you need backed up, but find getting all the files into a single place to burn a CD-R is a pain, this is the tool for you. If things get too big for a single disk, a little filtering action, and voila, you have two directories each less than 700MB. The amount of customization possible here is rather mind-bending, and if you spend the time to do it, the flexibility of the program will reward you.
There are a few things I would like to see in it though. First is the usability for non-technical people. There is a help system, and a well-done wizard to walk you through things, but to the truly dense, it will present a problem. While this is more of an issue with the user, it keeps out the non-technical, the very people who would get the most use out of this software. Those who can write scripts will feel right at home, and marvel at the time this will save them, both in terms of setup, and maintenance.
The other little thing is looks. This program isn't pretty. It is however functional, which is enough for me. Don't expect flashy graphics, animated characters, or even much color, just standard windows dialog boxes. Menu items are more or less where you think they will be, I never had to grope for anything, pop-up help is plentiful, and the help system is thorough, just a little bland.
Overall, Bash scripters will feel right at home, and those without shell-ninja capabilities will have a lot of the file manipulations from Linux in an easy to digest, graphical format. Almost all of the UI blandness is a moot point, because you set it once, and it just works. After the initial configuration, I forgot about it for most of a week, and it kept doing it's thing, and that is very good. If you have a use for this tool, it is hard to figure out how you lived without it. To those with a decent understanding of the windows file system, this program should pose no problems. 7/10 unless you are maintaining a peer-to-peer network, where it jumps to a 9/10. µ