I have 3 pieces from Rev'it and 2 from Klim. I like the way the Rev'it gear moves while wearing it better. I also like the layout of pockets and zippers better. The Klim feels more substantial. I bought the different pieces for different reasons and at very different price points so I don't think an apples to apples comparison would be fair from me. However, I do think both companies make a nice product. If I had to pick one it would be Klim because I feel that there is better protection. Also what I own from Klim doesn't require separate layers for rain protection. All my Rev'it gear has multiple layers. That is something I find mildly inconvenient in my riding climate.
It all started with that P.K. Ripper.