before I say anything let me tell you one thing from my personal experience - for streaming HD video when WiFi works its a delight but when it doesn't its pain *******, WIFi is never reliable, though it depends upon distance,barriers, router 802.11 g/n,access points etc.
I have been using ASUS HDP R3 to stream 720p/1080p films. During last few months experience I found 9 out of 10 times it worked flawlessly, but sometimes video stops, lags........
at the price you have quoted you won't get a robust media player rest aside WiFi
points
around 8K
1.ASUS HDP R3 is versatile for file formats, has WIFi, sloppy interface, crappy remote
2. WD TV live is not that versatile in handling file formats, no WIFi, provision for USB WiFi Dongle, super interface and simple remote
above 10K
3. Popcorn hour players are excellent in all respect, some of them can be converted into a jukebox by adding a BD drive, that means you will have a near HTPC
my only suggestion is if you are planning for using a media player for seeing loads of 720p/1080p films for years without issues, buy any of these and a 11n router
If possible don't try for WiFi streaming, buy good quality USB hub and connect all the USB drives in it to the player, no need for router, computer and so on
you will get coaxial and/or optical from a good quality media player, but those are for adding meaningless feature, I never understood what a 1080p media player has to do with coaxial port!!
Don't even think of using it as DAC for music, if you need quality sound get a decent standalone DAC, quite a few like ODAC,SMSL,FIIO are VFM, do some justice to Norge 1000, its a superb AMP at that price, I myself use one
choice is yours
Arnab