Are these compatible? I currently have an Infinity system and I don't like having to stick my Garmin up in the window for guidance. I know many of you hate the factory NAV systems but they work fine for my needs so please don't tell me what other system I should get.
So, if I currently have the Infinity system will the RB4 hook right up with no issues? I read that the RB1 will not work but the RB4 info seems a bit vague on the subject....

 

I don't think that's true. When I researched this some time ago, I understood that the RB1 will work and is considered to be superior to the RB4. Take a look at this comparison.

http://home.comcast.net/~mr.scsi3/RB1_RB4.HTML

 

I have found that the RB1 will work with the Infinity system if a special harness is used. I also finally found that the RB4 will indeed connect to the amp with the factory harness. I found that same link that you posted too.
I agree that the RB1 is the superior unit in most ways but when they never come up for sale at a decent price, but the RB4 does, then sometimes you sacrifice....