I rode my k4 600 around for 12 yrs, put 50,000 miles on it and never thought it needed more power. It has plenty for 99.9% of the riders out there, unless you are 250 lbs. Just gotta know how to ride it.
That being said, I did an engine swap to a 750 earlier this year. It is without a doubt, a lot more fun. The extra horses are right where you need them. I think the 750 is the perfect street bike. But maybe I'm biased. That new naked 750 is sweeet. I would think about that one too. Unless you do track days. But if you ride street only. I might consider this if I were looking for a new ride.
750 has more torque overall, certainly when it comes to more low-end and mid-range power. It makes it a much better bike to ride around town. The 600 isn't going to be lacking power for anything other than sheer bragging rights, but the 750 will have much better power delivery for regular use.
Not sure if that is Anthony in those vids(especially not vid #2). However, in the case that its not him, are you still interested in knowing about his scrotal region?
You just can't mess with geometry settings without knowing exactly what you're doing. By lowering the bike you could alter anti-squat properties,trail,rake,cog etc. a few mm have a bigger than imagined impact. Please be advised by a knowledgeable person before proceeding to any changes.
Kenneth try out a 636 Kawi if you can. Everyone should sample that motor. Anyway lots of guys like the bigger bike because you don't have to shift gears as much. I never understood the notion because if I didn't want to shift gears I'd buy a fuckin Burgman 400 and call it a day. I personally love tap dancing with the smaller bikes. You can't go wrong with any 600 or Suzuki's 750 and if you get bored with either one, then you're doing it all wrong. Coming from a 300 the 600 will feel plenty fast.
Can I ask how many miles you actually put on the 300?