the built in toslink outputs 96/24, the airport tops out at 44/16. mine did at least. (2nd gen). in me previous system (creek, totem, musical fidelity) i did not hear much of a difference between the AE and and the direct toslink connection, in my current one the wired connection is quite a bit better, and USB is better then toslink (usb is 1m, toslink 3m) that being said, 10 meters is quite a long run, you should try it out, i wouldnt be surprised if the AE would be better then running a cable that long. experts usually recommend a max lenght of 1.5m for coax, 1.5m or less for usb and i guess 5m optical. i have read people say that the old AEs sound better then the apple TV, i cant confirm from own experience however. good luck!
Firstwatt J2, AN-J LX HE, Lampizator L4G5.