I learnt to ride in a TU250. Mind you, never got above third gear....
Over here, in order to get the driving licence, you had to undergo an examination with a given circuit doing tight turns, controlled braking etc. That is, when you get your licence you have never driven a bike on open roads!
After I got my licence, I got myself a Suzuki GZ250. It has the same engine, but with a cruiser look. I can tell you I still keep it 10 years later -along with my CB750, CB350 etc-. It is reliable, easy to ride, and not thirsty at all. Maximum speed is around 75 mph. I use it for commuting, it is nimble among traffic.
That being said, if I could only afford one bike, it would not be a 250cc. For me, the perfect engine size is 400cc-500cc. Powerful enough for the highway, nimble enough for the city traffic.
I always liked the TU250 looks but what's the point of getting a retro bike when you have a real retro?