et al:
Any remote sync location has inherent weaknesses due to:
- Network conditions - local and remote
- Remote server reachability and response times
- Maximum concurrent connection limitations imposed by the service
- Bandwidth throttling measures employed by cloud services
These are limitations sync cannot overcome, any more than your web browser can.
For the optimal experience, I suggest you use a remote sync option only when you need to. Just having a Dropbox, iCloud, etc. account does not make it an optimal solution for all situations.
This doesn’t mean you can’t successfully use a remote solution. It just means there are some stumbling blocks that can occur when using them - blocks caused by the conditions mentioned, not our sync engine - and they can inhibit proper syncing. As people often say, YMMV (your mileage may vary).