And that ain't the CRF250X engine either, it's a shared engine with the CRF250L. Totally different than a CRF-X.
I'd be all in on a true SS 250-400 but I'll take the super light feel of a Ninja 250 anyway. I just spent a few miles on one in twisties (2012) and it is super toss-able. Light crank? Low rotating mass? Skinny tires? Whatever it adds up and it works. Even the shitty little front brake works alright. Better shock/forks would be welcome and a few aluminum components wouldn't break the bank but this is all you can get stock sooo.
And I have a EXC530 that gets sumoto wheels swapped on. It climbs north of 280lbs with 17s and is basically stripped to bare minimum head/tail lights and switchgear. No mirrors, no nonsense. Even the "light"/exotic DS bikes aren't all that light.