It actually makes it dead trivial. Plug your 800 into the cable, and in a minute you see a "Sync Complete" pop up, and your track is on Garmin Connect. (That's on Mac OS X, though, although people using Windows have reported similar routine success.)
What problems are you having? With an 800, you can always use manual upload as a last resort, which isn't too difficult.
As for the last question, I'm always amazed by people thinking that another brand will necessarily have better software than Garmin. The brands I've heard about for cycling are Bryton and Mio/Magellan (Mio in Europe, Magellan in the US).
Guys, I believe the OP is talking about courses, not activities. Sync and export only works for activities AFAIK. He wants to get his course from Garmin Connect to his 800.
There have been a few others with issues sending courses to the device. I'm not sure what the solution turned out to be, but downloading and reinstalling Garmin Express is not going to be the solution, unless your current version is quite old.
