Even if the X360 sold 100M consoles this gen -- all of the Xenon and Falcon chipsets have a good chance of choking in the next couple years, if they haven't already. Thus, if the Jasper fail rate was even 10% over a 5 year span, you'd still see the "XBox 360 failrate" at like 24% over the entire history of the console. It'll go down as the most fail-prone console of all-time, despite the fact that MS has basically fixed the problem with the latest model.
In short, Jasper X360s are worthy hardware. You shouldn't be scared of one. Its the other models of X360 that skew the numbers. Buy new, and you should be okay. Buy used, and you're asking for trouble. Then again, many X360 fans claimed RRoD was gone after the Falcon, and that, apparently, wasn't really true... but I think in this case, the tales of the Jasper being relatively safe from RRoD are correct.
I have a Jasper myself these days, and it hardly gets hot at all. My slim PS2 seems to get hotter, even.