the definition might be the worldcup which is different from many race series and locations.
For me (180cm@88kg) the 130,107&87 is the way to go because our Japanese race series has many gusty spots with larger wind holes close to the beach. On top of that, with a couple of other sailors around and not have the great pumping techique like the pros, I have no other option than the 130 in lighter winds.
BUT, this is only for racing, which is the targe for the iSonic. If I wouldn't be racing, I would be on the 117, hands down. A perfect size board with with much more control. However, in this case, the Futura would be a worth option as well.
Hence I do recommend you to go BIG, or go home (Saying from Kevin Prittchard) or check if you will participate in races with unstable winds.
Just my two cents.