A-1 2007 or 2011

while i have had an outback for the past 4 or 5 years i have never been exposed to an AI. i am planning on purchasing an AI before the warm days of spring and am looking at the available information on the 2011. am also talking with the owner of a 2007 that is for sale about 150 or so miles away.
there is, of course, a noticeable price differential between the boats.
can any one list for me the changes - improvements between the 2007 and the 2011 to help me make up my mind?
thanks in advance.
wally