Dimitri - what will be different on the 4g 7m screamer, the 2011 was way too fast a twichy. The 2012 7m rengade produced more power...
The (2011) SCREAMER 7 and the (3G II) SCREAMER 7 is a little different, not as twichy as the 2011, better pop, better hang time, and better looping for crazy kite loops. So right now Momi and I have been working on the (4G) SCREAMER kites and we are having a hard time making them better then the 3G II.
Now concerning the RENEGADE 7 (3GII), it is a totally different kite then the SCREAMER 7. The RENEGADE 7 (3G II) has a little more power because it is has a lower aspect ratio then the SCREAMER 7. I hope this answers your question.