Is there a Quark 125B thermal problem?

[BrianG]

Really, the stock setup should be "good enough". If it thermals, then Quark support should be notified. These types of mods are done to make it run more reliably, so any mods are bound to make improvements if done right.

I haven't noticed any runtime differences, and I can't see how that would be affects. What it does do is allow you to run much longer (just about indefinitely) without worrying about whether it will thermal. If that's what you mean by runtime, then yes, it runs MUCH longer. :)