I thought I read somewhere in the last couple of years that the XM platform would ultimately win out. If they launched a new XM satellite would seem to back that up. I have had both and would give the edge to XM but not by much. Had a 2014 Toyota Rav4 had the worst reception of any vehicle with SiriusXM I have driven. Dealer insisted there was nothing wrong with it. Moved on to 2019 Honda Pilot, still get the occasional dropout here and there usually in the same locations. Live in the mountains and lots of trees to block the signal around here. Usually steep hill with a cliff on the south side will always block it. There is a 6 mile downhill grade eastbound on the Mass Pike I-90 that goes from Blandford, MA through Russell to Westfield, MA and you can keep the signal most of the way down until near the bottom before the Woronoco Bridge where the runaway truck ramp is, and the south side of the road is a steep cliff, the XM signal always goes out there.