Yea data conversion does suck. But it's a fact of life, and it's a part of what I do for a living (Systems Adminstrator). And I've had a LOT of mobile devices (and services) in the past. Data sync'ing between different types of devices and software is hit or miss. Even with standardized data exchange formats (i.e. vcard) can be hit or miss.

With all of that I've honed my data keeping to a fine art. I have one master copy in my desktop PC in the application Evolution. Evolution is my master copy, and it's never updated from any other source. Ever since I started doing that. It's been a lot easier to maintain my data (mainly my Contact which what I'm most interested in)