I have had my jonway VIP for a little over 3 years and have never had any real problems.
I cant say if the new ones are good, but i do know that prire to 2008 jonway had some poor scoots and sales droped big time, so they stepped up the game in 2009.
If you do a good PDI and catch any problems first off, you should be in good shape.
Take a look at this do as much of it as you can.
http://www.chinesescooterreference.com/pdi.htm