The derogatory approach of considering Intellect cells as chea chinese stuff and Sanyo ones as top notch japanese stuff is completely false.
As perfectly stated above, every cell model in the past 20 years has vented or exploded at some point in their R/C use... regardless of make and model.
Intellect, GP and Sanyos are all world class companies, probably now all 3 operate out of China these days, and would not be so widespread if they were "junk".
The fair analysis of the failure rate of IB4200 is that they own most of the R/C market at this stage, hence are matched in higher volumes, so volumes are a factor
Another factor is that it is a fact that IB works very agressively with the R/C industry and are probably willing to push the envelope a bit more - especially considering that they ve been gaining market share tremendously in the past years.