Since 2013 I'm using and working with the Raspberry Pi as audio streamer.
I'm also contributing this or that to certain community projects.
Why Raspberry PI?
The Raspberry PI family is by far the most successful single-board-computer (SBC) out there.
Even though the PIs architecture and hardware can NOT be considered top notch (other SBC do (much) better at similar price levels), a PI can very well serve the purpose - to act as a rather serious audio transport.
Not as an off-the-shelve installation, no, it requires some tweaking to get serious quality audio from that device.
What makes a device like the RPI a success story is its wide market presence,
great and innovative SW (manufacturer+community) support and OEMs flooding the market with all kind of (quality) gadgets.
Many other SBC companies failed to succeed (beyond becoming a niche product), because they were not able comply to these factors - even providing a much better HW wouldn't help. Without being able to address the key area - proper and long-term SW support - these devices are pretty much worth nothing.
Providing, evolving and maintaining quality SW is a continuous process over a long period in time. That's what many manufactures underestimate! And that's why they usually fail.
And that's the main reason to go for a PI.