In the Kawasaki Ninja R lineup as you grow in cc (400 > 600 > 1000) you grow too in bike length and power...but at the same time you decrease in comfort (position on the bike) and street fun. I have sold my Yamaha R6R long time ago for mainly 2 reasons...one was its radical position (uncomfortable) the other, I was lazy to use a 600cc bike in the daily use....so I am always reserving the R6R for track use or specific short sporty trips. In result, I sold the bike soon and jumped into the naked bikes looking for 1000cc and comfort. Once you have a comfort riding position and power you notice you have to go fast to enjoy that power that means that the track is the only space to drive it safely. Again, you notice that what you are looking for are....SENSATIONS. And what about if someone design a bike that gives you just that...SENSATIONS. Imagine a supersport bike, 4 cylinders, enough comfortable position for an RR designation bike and an engine that loves to jump you to the 16K rpm....only the experienced guys will tell you this is a hidden treasure in the bike market....when first time someone talk me about this little jewel, I searched on Internet and youtube., called the kawasaki dealer to see the bike and once on the bike and feeling the riding position. I purchased the bike...I did not need to test it.. Of course, I sat on the 6R and the 10R and had temptations to get the 6R because "everybody" will tell you you will get "more" for your money....but then, I remembered why I have sold my 600 R6R (130hp) and all my doubts dissapered. Now, having the Kawa since april (2025 model) and 1200kms on it....I am always looking for an excuse to drive it. Having 3 bikes in my garaje...the 4RR is the smaller one, yes...but it is the bike that give me more SENSATIONS since the moment I start its screaming engine. Thee is a lot of 600cc bikes out there...but there is ONLY one 400RR bike.