Will you notice a difference. Absolutely. The 600 will respond much faster, and you can spin that engine up way higher. Unless you can break the 80mph mark, in second gear on your 500, expect a different animal underneith you.
You can buy bar riders that will make it slightly more comfortable, but the biek was designed for that riding position. You might want to look around at other less extreme bikes if you are more interested in cruising than pure track day power. The ZZR-600 is considered a really good bike. Pure supersport demeanor, all day comfy. Ditto the Honda VFR800. The SV650S will be a good blend of what you are used to and the more extreme GSX-R. It is also a more useful bike aroudn town, as it has more torque and you need to spin the engine less. It is also one of the most popular club racers these days. If you ever want to do a track day, it is certainly up for it. Similarly, non of these are classes as “supersports” and so should have a much lower insurance rate.
There are lots of choices that are 95% as fast in 95% of the situations as the GSX-R, with more practicality than the GSX-R or other 600cc supersports.
Whatever you end up with, enjoy and be safe.