I'm going to get a new head unit for my S soon, and have been waiting for the CDA-9857 to come out. I have an Alpine V12 amp (MRV-F345) that has the amp link on it, and was wondering if anyone uses it. I don't know if the CDA-9857 can use the amp link, but I know the CDA-9855 can. I tried to find out from Alpine's website, but didn't see anything about amp link on the CDA-9857. I'm just wondering if it would be better to get the CDA-9855 if the CDA-9857 isn't compatible with it, or just get the CDA-9857 anyway. It seems like a pretty cool feature, but I don't know how practical it is or how much it would be used.