The R&D focus a lot on top end speed and confort with out changing the planing ability and acceleration for all the iSonic range this year. So the iSonic 111 2009 is faster than the previous model and more confortable. You will make a big jump from 2007 to 2009 model.
Yes the 6,7 still working very well on this board and you will feel that the board glide more than before and need less power on the back feet.
All the best