If one side is always the master and the other side is always the mirror of this, then you can use clone up / clone down to sync deletions.
Currently for two way sync, we explicitly force you to remove files from both sides. This is because no matter how much care is taken with file deletions we have users or companies who come back with "I l accidentally lost my files, how do I get them back" so we'd rather force this into being an explicit action. We could do some smart tracking of deletions like the product you mention but even that is not totally foolproof (and lost data obviously matters). For example, it requires to have 2 folders (for each side, local and remote) to act like alternatives to Recycle Bin, it won't delete files, but keep them in this folder. One must not delete this folder accidentaly. You must sync files only on one computer, with same profile. And so on. Such approach fails, if one of these requiremnts not met
For example other Sync solutions like SugarSync also recommend explicit delete on both sides. See http://sugarsync.hivelive.com/posts/167bf8be0c because it is the most foolproof way to ensure data is not "accidentally" lost.