I entirely sympathise with your frustrations.
The basic problem is there is too much distance between the front and back footstrap plugs.
One day I plucked up the courage to rout some holes in my iSonic 105 and install some extra footstrap plugs behind the exisiting front ones. I reduced the distance between the footstraps by 7.5 cm and it tranformed the board.
I have since owned an Falcon 124, iSonic 121 (2010), iSonic 97 (2011), iSonic 90 (2011) and they have all received the same footstrap treatment and everytime the floating front feeling has gone away.
If you would rather not start cutting holes in you board, you could buy a 2013 iSonic. I got a new iSonic 110 last week and compared to the 2011 boards the front straps are 4cm further back.