There are some advantages, at least in the case of a programmable mouse like the one in question. Once you've got all seven thousand buttons programmed Just So, you can then upload the profile to the cloud and have it automatically synced with any other machine you might happen to use the mouse with -- say, a PC at a LAN party.
Of course, this is about as small as an advantage can get, since I'm struggling to think of a person who cares that much about their mouse profile who wouldn't also lug their own PC to the party. So it's not all disadvantages, it's just nearly all disadvantages.
It's a "professional gaming mouse", it's supposed to be used by progamers (the ones that regulary go to LAN tournaments, have many gaming computers, and destroy 20 mouses a year). I can see how syncing mouse settings between mouses can be useful for them.
That's true. The difference is that the cloud is a really good way to solve collaboration and sharing, and a really poor way to solve settings syncing for a device that is not otherwise internet-related.
just save the settings to a human readable file instead of something ridiculous like The Registry then they can symlink it to dropbox if they care that much
Of course, this is about as small as an advantage can get, since I'm struggling to think of a person who cares that much about their mouse profile who wouldn't also lug their own PC to the party. So it's not all disadvantages, it's just nearly all disadvantages.