Overall, i suggest that you go and check out these bikes. As i said, they are nimble, light, quick and do not need as much maintenance as the four strokes. Check them out now!!
The think that i like with this bike, is its ability to stay with the 250f's. As the 2-stroke generation is slowly dying, the 144 will bring back to life and the old days of "ding ding ding". :D Being nimble, light and fast, the 144 will make up in areas where time is lost on a four stroke.
There is not much i don't like about the 144. The only thing wrong, is that they may or may not be able to race against 250's. That is the rule so far here in Australia, but i know that it is legal to do so in Europe.