You in a biased site, but I was there a week ago ninja 250 or 250r. Easy choice for me, FI vs carbs on the Ninja. Take the FI!! And the Ninja 250 has peaky torque, while the single is just made for newbies and experienced riders. Plus the CBR looks more modern and hey Honda is better quality than Kawasaki.
I think most here would say to get the Honda. Ask the same question on a Ninja forum and they will say the Ninja.
At first the Ninja was first choice and for a time the only choice for a 250cc bike here...I then found out about the Honda CBR250r. price was great. i did alot of reading about them and everything i came across was positive.
i checked out both bikes sitting on them, feeling the weight... the Honda is a bit more upright sitting (which i wanted) Then(as Acura says) there is carbs vs Fuel Injection. better low rpm torque on CBR. more modern look and instrument panel. Top speed isnt so much of a factor. I can cruise at 130kph all day and is as fast as i want to go.