lots of variables here
but there is no reason for streamed music to sound worse than files that are downloaded, all else being equal
but all else is never equal...
personally, i have worked hard, learned alot, and implemented a very high quality streamed music front end... it is every bit as good sonically as cd’s played on my cdp (which is also of top quality, one could say that they may sound a little different -- but not clearly better or worse... this due primarily to the output stage differences of the my cdp’s and my dac that plays streamed music)