You've been told very wrong. The CVT in the 650 is nothing like you've experienced,
Here's another long term rider's view of it and if you read the review you'll see the comments about the performance surprised the reviews big time.
The nature of an advanced CVT gives you sweet spot power all the time. Again read the forum and the review - you'll see how wrong you are.
ALL low CC bikes will need to be wound up for performance - an earlier 500 will feel much better than you are used to but that will soon get old unless you are willing to spin the RPM up.
Weight to power on the Ninja 250 is decent if you are light but it only starts to move in the 7k + range and you really need to watch your insurance costs until you are 25
If you are not touring then you might even consider a light dual sport as they are geared for quick acceleration and your riding skills will improve enormously if you get off the pavement for some riding. Those off road skills will last a lifetime and there are excellent courses available.
Dual sports are very tweakable as well so you can have fun with many upgrades.
( so are Ninja 250s to a point )>
They are fun and nimble around town as well.
If you ask for advice you need to be willing to listen to experienced riders, do your homework and not bring misconceptions to the table.
To address the CVT issue, its not a "misconception" its just something ive experienced on my bike while i was working on it. Without the CVT attached (no belt on) the bike actually reved up to 11500RPM+ (yes i have a no rev limit CDI) and after the installation it of the belt it shot down to 9500RPM of course it will decrease due to friction but i wasnt expecting a 2000RPM drop... Like i said im just going off from prior experience and dont mean to sound ignorant or arrogant, im here to learn just like everyone else! I have no problem in high revving machines

7K+ is A OK with me, however if its bad for the bike mechanically im not totally sure

ive never riden a REAL motorcycle before, i just know that my CVT driven scooter likes to be between 6500-8000RPM for cruising (80-90km/h). Like previously posted, im trying to stay away from CVT driven scooters no matter what the CC's, i can attest to its fuel consumption and smooth riding but im kinda looking for something different

If i go with a 250 ill probably want to sell it after just one season for something with more power, so i think if i stick with a 400-600 ill at least keep it for 2 or 3 seasons because theres only so much power i need

im not that power hungry, im satisfied with my bikes output but at the moment it just cant serve the purpose of long cruises at high speeds which i intend to do in this season (looking to get on the highway and get out of town a month at a time, along with general city use). I have thought about the DualSport idea however i just dont think it really suits me, however they do look really badass! I do know they are easily modifiable with upgrade parts galore which can be found almost anywhere, but like ive said in the previous post im looking for a sport/touring type of bike

I plan to do some work on whatever bike i get probably not upgrades just yet but things like valve adjustments, new coils, spark plug, gaskets, etc. you know, the small stuff which keep the bike working at its peak performance with little cost

nothing too extensive like a $400 exhaust system or a $200 carb etc. etc...
"If you ask for advice you need to be willing to listen to experienced riders, do your homework and not bring misconceptions to the table."
Like ive said on many other forums, everyone is entitled to their own opinion and yours matters just as mine, so in essence im willing to listen to you if your willing to listen to me type of deal

Im willing to learn

Im no flamer, ignorant, arrogant, keyboard elitist, btw i can keep going

but im sure you get my point. Really appreciate the info brother.
Regards,
Armen