Anyone using a portable as their primary server?

Curious if anyone uses an Astell & Kern, Pono or similar plugged into their rig? Meaning: not for portable use but as primary storage / dac ?
I use an iPod touch with a Luxman iPod dock to stream Tidal and play my iTunes lossless downloads - sounds quite good
Looking hard at a Pono for DSD and high rez audio playback (vinyl junkie). Wish my system had balanced operation as the Pono would really start making sense. For me the portability of the Pono is the key and it would be used with headphones (modded for balanced operation), car, and main system. This pretty much rules out computer audio system, but for me it will be a nice stepping stone into the digital world. Some say as good as a $2000 DAC so it seems like the bargain of the century. The onboard storage seems a bit limited especially for high rez material, so may see if I can kind of hot swap SD cards.... and if that is possible then maybe one just keeps a collection of Micro SD cards for the music. Pricey memory, but very compact I suppose.