@fuzztone Oh, I see. I know of no reason one wouldn't be able to play tracks one owns, without needing internet access. The RS250 is on the local network, the files are on the local network (or attached directly to the 250). The software on the 250 doesn't need to go check if your license is current or anything like that; there's no license that has to be paid for monthly or annually or anything. You bought the software when you bought the unit.
@beatlebum Glad you're liking it! That's promising for me. :) Those Luxman integrateds are nice pieces of kit.