Note: pricing for this product is in US$.
BeInSync does four particular tasks — synchronising, sharing, providing remote data access, and backing up — and it does them very well. There's no confusing of these tasks, each of which appears as a giant button in the cleanly designed interface. If you opt for the smaller 'Launch BeInSync' button, you get a more sophisticated interface, but with the same four buttons at the top.
BeInSync handles file and folder syncing a little differently than other sync products I tried in that its sync function does not actually store your files on its servers (for that feature, you'd use the backup button); it simply syncs files between computers that are online.
BeInSync is also the only application I tested that doesn't hand over both copies of a file in the event of a version conflict. An icon by the item in Explorer and in the BeInSync application alerts you to a conflict; but unless you are using BeInSync's remote-access feature, you won't be able to compare the versions without going to the other computers.
On the plus side, BeInSync has the best file-sharing features of any app I tested. Unlike the others, which make you type in the e-mail addresses of people you want to share files with, BeInSync lets you import and authorize all your Outlook, Outlook Express, and Windows Live Messenger contacts. SugarSync has a similar feature, but it lets you share only photos. Furthermore, in BeInSync you can give people read-only access (Viewer), full access (Participant), or full access plus account control (Administrator) rights; Live Mesh has options along the same lines.
One of BeInSync's most potent — and frightening — features is called Access. Simply by enabling this feature, and by keeping the installed version of BeInSync running, you make every drive, folder, and file on your entire computer available via a Web browser to anyone who has your BeInSync user name and password, and who is also running BeInSync. And you can't limit this control by using the Share feature exclusively, since sharing works only if the Access feature is enabled. This function strikes me as powerful to a degree that most security-minded users would find unnerving. It's undeniably convenient, though, and it's much easier to set up and use than a home network.
BeInSync's pricing is comparable to SugarSync's: An individual user paying US$100 for one year receives 50GB of online storage from BeInSync, but a little more (60GB) from SugarSync. With its multiple features and easy-to-use design, BeInSync is worth the extra money. But the inability to store backups on BeInSync servers, along with the service's poor attention to version conflicts, made me think twice. If the company addresses those areas, BeInSync could become an excellent business tool for managing your data.