I have a 4-tuner Premiere (w/ Comcast). Everything works good. Was looking at possibly getting a Stream in order to do out-of-home streaming of live channels (to portable devices...iPad and iTouch). Can this be done with a 4-tuner Premiere? Or is it really only for the Roamios? Also, if it can be done, will the Stream just use one of the 4 tuners on my Premiere without disturbing the current viewer in any way? Or does it work some other way?