Quote Originally Posted by quickdodgeŽ
A couple of other differences, then, lolol:

Sirius has a lifetime subscription for $500, XM's highest level is a 5 year term for the same price. With Sirius, you get free satellite radio on your PC, XM has it for $4/month.

Channels:
Sirius = Howard Stern
XM = Extreme XM

Sirius = Maxim
XM = Playboy

Results comparison review:
Sports = Sirius - based on wide range of channels
News = XM - has top brand name newscasters
Talk radio & Entertainment = Sirius
Hip Hop/R&B = Both
Pop = XM - very good mix
Rock = Sirius

Later, QD.
it WAS 4/month until they increased their rates to match Sirius's rates. now they are equal in every way in terms or pricing it seems. the rest of your arguments are valid

I love the house music channels on XM btw, they have like 5-6 of them that cater to different styles of dance music. they have also added some channels in the last few months, i can only assume to help bridge any gap they may have had in their programming and to be exactly (as best they can) as Sirius.