Sold the dAck! to pay for a modded Squeeze Box. Had no issues with it (well built, good value, good service, personally no problems with the battery function). Chris has done this on the side for several years so he's not available 24/7 and builds in batches so you might wait a couple of weeks extra to receive your order. Frankly I'm a speaker guy, so the differences between sources are easier for me to live with than other audiophiles. I will say that I've tried switchable (between battery and A/C) sources and amps where I live now, and they made no audible difference. Others here at Audio Circle have said the same.
OTOH if you have dirty/grungy power I'm sure you could hear the difference instantly, especially with digital sources. Factor your utility distribution condition/age/customer mix (avoid industry), age/condition of wiring in the home, age of appliances, etc. My previous house/appliances was very average (50 year old with horribly mangled wiring in a subdivision) but no heavy industry where power conditioning made almost no difference. My current place has close to ideal A/C.