You dont need pros and cons about Infinity. The reference seris is good to but if you get Kappa series they are top quality products. I personaly like infinity alot. My setups infinity everything cept subwoofers. And thats because i got Atlas 15's :D
im not sure of the actual step-up from the infinity kappa perfect component sets, but i know of something considered higher.. the rainbows are what, $9000? i wouldnt pay for that, maybe $1000.. but not $9000 for speakers. people have said infinity gives you the best in its price range, and among the best overall. feel free to correct me because i am going by what other people have said.
Infinity is a speaker company, they take pride in speakers for both home and car audio. But I'm not sure about their amps, they really don't make any home receivers so I can't figure out why they threw some out for car audio.