I have been running the Kali reclocker / Piano 2.1 combination on RPi 2 for some time.
This represents a fantastic value and great sound quality at very little money.
Running Moode 2.6.

Been doing lots of A/B testing RPi2 / Kali/Piano 2.1 against Desktop PC / Windows7 / JRiver / Asus Xonar Essence STX sound card.
Started the same song on both devices at equal sound level. Using large Genelec monitors.

I am addicted to 96K resampling. Resampling brings out the digital effects and soundscapes
on modern music. So both palyers were running resampling at highest quality.

Some friends could not tell the difference between PC / RPi. They could not believe
that the small, inexpensive RPi could sound this good.

After many tests, I can hear only one difference. The Kali/Piano/RPi/Moode combination
introduces a small amount of soft compression on the sound. This is a matter of
opinion, but I would like it without compression. The PC/Xonar Essence is a bit
more lush and open. The RPi slightly compressed.

I have plans to test Volumio. Also the Volt amplifier with Sparky SBC.