What dirt bike would be better for me? 250 or 450?

[Brandon C]

i am interested in buying a bike in the spring. i am 15 and i am 6 foot 2 and weight around 160. i want a dual sport bike that would work as my first bike. i have been riding on 2 and 4 strokes since i was 9 years old. right now i own a 1988 honda xr200r and i think it is to slow for me, i dont think its running on all 200cc's if you know what i mean. i was thinking about buying a ktm 450exc because i love ktm since i previously owned a 2 stroke ktm 65sx. i think the only other brand i would go with is honda because i have ridden honda's and im pretty impressed with their power and handling. the only thing i dont like about the new hondas are that they are wide ratioed 5 speed and i prefer 6 speed, do the WR 5 speed have any advantage to the 6 speed other than a longer gears? What bike do you think would be better for me 250 or 450? honda or ktm? 5 speed or 6 speed?