What you will find is that the new cells are charged at a higher rate, thus putin a high load onto the cell. The container that is made to hold the inners is appox the same as the lower capacity cells. You get a lot more stress on the cell , so when they let go, they go with a bang in general.

The old cells wont take that tpye of stress so vent a lot sooner.

Good to see you picked up on the series i put in.

But the load rating of the the cells is still much higher than the lower capacity cells.

The reason you have been tormented by he statement that the sanyo have the same discharge rate at 10 amps, is So What?? They dont perform on the track. Again you stated the the IB cells would perform better on the track.
But 10 amp discharge is not the track, we know this so why compare the 2?? It makes no sense to compare them, the IB are a better cell.

Simon