i'm looking at using an alpine sxv200v1 connected to an alpine deck. alpine tells me that the connection to the deck is not standardized (its not ai-net which i could get an extension cable for) so i guess i'll have to get a fakra extension cable? is this what you guys have had to do??

I have used antennas interchangeably and had no issues. If I were say BAF and were installing for a customer I would never use XM with Sirius but if it were my friend for freebie I'd definitely do it. Those antennas are powered by 5V sent down the antenna connector from the XM/Sirius receiver so either will work as long as they get the 5V they need to power on.

My XM factory unit in my Z receives like a** anyway. I have an aftermarket in another car and it's reception is just as bad. XM/SXM turned off the terrestrial feed here in Orlando and since then if I drive under even a small Oak tree my XM signal drops out, practically unusable in my area unless I'm in open sky. I wish they'd turn terrestrial back on but it's not likely. I think the first time in the history of both companies they actually turned a profit last year and it was barely in the black. SiriusXM is still shrinking, every year they reduce expenses by laying people off.