After this season if the cells stay as they are, I'll be using GP's next year.
I bought some IB's and GP's at the same time, both have had similar (ab)use. The IB's have lost quite a bit of performance, the capacity is still there but they have lost a lot of punch. A couple of packs have leaked too which is never good. The GP's still feel almost like new cells, havn't vented/leaked and still have almost all their capacity.
Fair enough the IB's had a bit more punch to begin with, but not enough to put up with the cells fragility IMO.
I like the idea of Lipo cells, can't wait to run them

It's ok to hacksaw a pack in half to fit in my BJ4 isn't it?!