I use the Intaride system and I can't fault it.
I've never had a problem obtaining spares, they've always been very helpful when I've rung up or emailed and stuff arrives in a couple of days.
The audio quality is excellent and no-one realises I'm on the bike when I answer my mobile while riding....which can be quite handy when I'm supposed to be at work!!!
It does all the usual things like automatic music muting when a call comes in, you can use vox or PTT for the transceivers...really it does avarything I need.
I have mine set up with a transceiver for bike to bike comms and and other uses and it works really well and the music quality (stereo on the intaride) from my mp3 player is great. I've used it on quite a number of tours and it's never given me any problems.
I would recommend it...though I've never tried the Autocom or the Starcom. so I can't give you a comparitive opinion.
Good luck making your mind up...it took me a while, but I went to see the Intaride guys when I was looking for an intercom and they were very helpful, eager to implement a few small changes to accomodate my radio needs and were quite happy to provide all the technical information that I wanted.