I put 570 Km (well the bike arrived already with 85 Km on it...)

So far so good I've to say, it's a nice bike indeed. As I said I'd like more power, but that's as good as you can get in China without too much hassle.
You change the oil every 1000 Km? I've always wondered why is that, even with the car they advise change the oil every 5000 km, but back in europe I would change it every 15000 Km. Is it the oil quality difference? Or the air very dusty here? Still every 1000Km seems a bit too precautionary in my opinion.