Hello,
May as well throw my tuppence worth in. Ive flown Gs and now I landboard and kitesurf with StormsIIs. My main advice would be take your 12m out on light wind days, with someone to help you (instructor / someone who knows LEIs). The StormII kite behaves completely differently to a G (foil) and is nowhere near as forgiving. Trust me.
The wing tips have many settings and I'd advise the following setup until you know what your doing. Attach the the rear turning lines (red left, blue right) onto the slow turn setting and the power lines on the depower setting.
If your over powered at the zenith, with the bar depowered your best landing it and getting a smaller kite out. If not, get a feel for it, fly it safely and make sure you practise pulling your first QR with a helper standing by if anything should go wrong.
Dont be the generic twat on the beach the Jason Furness (Flexifoils Pro Team Manager ) talks about in this 45 min podcast. Def worth a listen.
http://www.dualbotic.com/downloads/KitesurfingPodcast4.mp3
Hope this helps, if you have any other queries re: your storm, pm and I'll help if I can.
Cheers, Chisp.