I did the time machine method over thunderbold ethernet adapter to my osx lion time machine server. Ran about 33MB/s, or saturated the usb2 bus so no complaints on speed. I created a new admin account and only transferred my personal account so there were no collisions.
Only ran into a couple hiccups, but there were the sort of thing a non-technical user would have been tearing their hair out over so not exactly wins for Apple there.
First, my dock process was maxing out a single core. The fix was to change my wallpaper and restart my doc process. Seriously. The wallpaper did not migrate, and dock was too dumb to deal with it and just ran full tilt wasting resources until I figured it out. Thanks macrumors forums for the fix.
Second, my photo library shows a bunch of missing photos. I tried restoring from time machine, then again from crashplan. Both had the same effect. Might have been some problem with upgrading to iPhoto11? In the end I ended up exporting my photo library to a new library, deleting all of my photos in my main library, then exporting them from the temporary library back to the main library.
My head spins thinking about trying to talk a family member through this remotely. It wasn't like I did anything fancy. Had a macbook air, used iphoto, backed up through time machine, upgraded to a new macbook pro, using time machine, migration assistant, and the new iphoto. All apple hardware and software yet it was still a very poor upgrade experience.
It worked, but took a lot of wasted time. Just my experience, I have no better method to recommend other than to hope apple addresses some of these issues.
