I have had both....... XM in a Yukon and Sirius in our X3. The reception was leaps and bounds better with XM. It probably depends on the area you live and travel but here in Houston XM has a ground based towers that provide excellent coverage in and around objects that block the satellite. The Sirius cuts out when you go under overpasses some streets with trees on it block the signal............ If I had it to do over again I would have put XM in the X3.