Best cloud sync solution

I am currently using CloudMe to sync my databases between Mac and iOS. At the beginning it worked very well, but now there have been several outages affecting CloudMe. What cloud solution do you use and are you satisfied?

In our experience Dropbox is the most reliable but slowest solution whereas MagentaCloud is the fastest & most unreliable solution (according to some user reports, we have never experienced any issues on our own). CloudMe/ are faster than Dropbox but there are sometimes server outages.