I used allway sync for 3 years and my satisfaction with it dropped over time. In the beginning it was working fine but the developers didn't introduce features that the competition got. allway sync is missing: pause button, time estimates, resetting sync meta data, ....
Especially one thing is annoying: If you sync to a backup disk and that disk crashes, you format this disk or replace it and use the sync profiles to create backups again. So far to my expectations! But allway sync still uses the old meta data that tells the app about previous synced file. BUT THEY ARE GONE! FACE IT! STUPID APP! ;) There is no way to reset the sync data within the app. Sometimes it helps to delete the sync meta data file by hand. If you find them.
But currently allway sync just crashes. Also the app has issues when syncing a large number of files. They also mention this issue on the homepage. What do they expect from me? Split the folders and jobs to reduce the number of files per job until the app "likes" it ???? Gimme a break.

I like it so far ! I'm using it to sync my backup files with Dropbox.

I like it because it's one of the few tools that will detect when a USB device has been inserted and automatically sync to the device.