Hi i have had my Evo 250 for a couple of months now and have found very little moan about, its a very easy bike to adjust to and feels very well balanced and the 250 motor has plenty of stomp. I had an 04 250 gasgas pro before which was good but showing its age so looked to replace it, alomst bought a 2009 gasgas! but when i saw the Evo it looked light years ahead in terms of design and build quality.
The only problem ive had is the sqeeking outer bearing cups in the swingarm, mine were catching so bad the swingarm was sticking! but this was easily fixed.
I have rode a friends 290 and its great but maybe a bit much for me, the 250 feels ideal i would recommed it to anyone looking for a new bike.