Sonicstage just transfers it to the player without any conversion as far as i can tell otherwise it would take a lot longer than it does.
Sonicstage for just transferring the files is fine, doesn't crash every time like the old builds (infact the new one seems 100% stable for me)
The problem is you are trying to use the software as iTunes, thats not gonna happen, there are tricks you can learn on Sonicstage if you have patience with it, but tbh whats wrong with just organising your music through it then just listening to the music on your walkman : /
I've never used the store on it though, or anything else though I just buy CD's.