Best Airplay Device

AppleTV?

Define "better". If you're talking about jitter than your DAC has asynchronous sample rate converter meaning suppresses jitter. If it is still not enough (jitter shows as a noise - lack of clarity) than perhaps additional reclocker would be better. I use AE but never investigated other devices that can play more than 16 bits since all my music is 16/44.1

Apple Extreme or Apple Time Machine which includes the Extreme wireless in conjunction with he Logitech Touch into a Metrum Acoustic DAC.

I began with the Express. Regardless of what cable you use with the Express it is still a bandwidth choke point.

How about this?

http://www.intl.onkyo.com/products/accessories/ri-dock/ds-a5/index.html

Or if your budget extends further

http://us.marantz.com/us/Products/Pages/ProductDetails.aspx?CatId=ReferenceSeries&SubCatId=0&ProductId=NA11S1

(this has a built in DAC as well but also analog outputs)

Thanks very much. Do you know of any reviews of the Onkyo or anyone who has heard it?