I'm a Dropbox convert (I hope!), but after having used Ubuntu One for a couple of weeks I notice a few differences from Dropbox. The most glaring difference is that the sync daemon constantly takes 500MB ram on my system (Ubuntu 12.04 x64). It hogs this amount of memory as soon as I log in, does it's initial sync/check but keeps the memory. All in all it seems to me that Ubuntu One uses more system resources than Dropbox. I am syncing the same folders and files with Ubuntu One as I was with Dropbox. Also, afte I log in Ubuntu One grids at 100% CPU for at least five minutes which can be annoying on a laptop, but is not a showstopper.
I'm wondering if this is a problem on my system, or if Ubuntu One is expected to use that amount of memory even when idle?