On paper, I think Gen 5 is the better bike. I would buy a Gen 5 over a Gen 4.
In real-world applications by Novice, Intermediate, street riders I do not see any evidence it is superior in performance. I have yet to see anyone switch from Gen 4 to Gen 5 and rave about how much better it is or instantly drop lap times, better quarter mile times, or better street manners. In many cases I see people doubt if the upgrade was even worth it.
I do read subjective comments about the performance that are not possibly defined by any measuring tool such as feels lighter, easier to go fast, looks better, and whatever else is thrown out there. I do not dispute any of these statements, but all of these statements are really opinions and unique to the individual.
I have very similar electronics on my GSXR1000R. I really don't think they are better for me at my skill level and riding style. In my opinion, what makes my GSXR superior to my Gen 4 and a Gen 5 is the mid-range power delivery.