Out of the box the Pioneer Elite X-SMC4-K Music Tap sounded awful. Everything we fed the system sounded muddy and at first I was very disappointed, even for a system going in my kitchen. After adjusting the advanced sound settings I was amazed at the difference. The Virtual Surround really fattened up the sound and worked like the BBE Sonic Maximizer. The surround term Pioneer used is a bit misleading, make sure you try your system with and without this function enabled, but I think you will be pleased in the expansive sound with it turned on.
Another area that caused us alarm at first was the start up time. No one wants to wait 20 seconds to start using a device after turning it on, but with the power saving functions enabled that is what you had to do. One quick change in the menu and the system would snap on and be ready to use instantly.
The menu system is surprisingly fast, much faster than my SC-37 receiver's Home Media Gallery function. We did have to play music through TwonkyMedia since we never found a way to input a password for the main QNAP folder system. TwonkyMedia is enabled anyhow on our NAS and is the primary DLNA / UPnP server for the entire house.
With the system configured the way we wanted it, all of the connections made and the music flowing the system performed as expected. With these types of devices there are always a few places where improvements can be made. The firmware is upgradable so if Pioneer does anything in that area the process is rather painless. Given Pioneer's track record of just releasing a new SKU instead of making significant updates to existing products, we'll just wish you good luck with that.
All things considered I'm happy with my purchase, at less than $200. Personally I would feel disappointed if I bought mine at anywhere close to the MSRP of $480. At that price you could buy a nice multi-room receiver and still have full surround sound in the main room while using the second room option where the Music Tap would be. I think the price is a big reason why no one is really talking about these Music Tap systems.
If you are looking to take advantage of your NAS' advanced media streaming features and you can find one cheap enough, the Pioneer Music Tap products are an easy way to add audio to small spaces without much fuss.