A small +/- difference in heat up time can be attributed to an extent to ambient temp and humidity. A second factor I expect is firmware which controls heat modulation probably by an eprom interface to the voltage regulator, thus there could be slight variability in the output of the algorithm. The former is to be expected, the latter is inherent in the performance design. Both IMO are insignificant.
Re the heat: First, as far as the "screws scalding" - um, I don't recall anyone posting that about a production unit. I think that issue was resolved. On mine the screws are no hotter than the casing. And let me be clear: I didn't mean that at 3 o'clock the unit cannot be touched above the bottom. I wrote that it isn't comfortable to "hold" above the bottom; that's a big difference. As it is given the Cloud's performance, I would guess that 3 o'clock will be used mostly to finish off a load and so for not more than a couple of minutes; many won't use that high a temp at all. At 12 o'clock, while the top of the casing is somewhat hot the bottom third is just very warm. In any event, it's perfectly acceptable to grip the unit near the bottom, and I wouldn't expect the user to continuously "hold" on to the unit anyway.
Where I was coming from in my "improvement" remark is that with the general public, if there can be a cause for complaint it will be found, and so if it's feasible to dial down the heat factor, that might be good. But thermal dynamics in a small form factor is a tricky business. Heat reduction usually takes the form of bulk and/or very expensive materials, or some compromise in the power sub-system itself. So that would be a design cost/benefit trade-off that VXC would have to make.
EDIT: So I did an scientific unscientific audio level analysis - I asked my wife with the bat ears who is super-sensitive to sound, to listen to the unit at exactly 3 feet; the only ambient noise is computer fans 15 ft away. She could readily hear the clicking. But she didn't feel it was an issue at all, not unless it would be next to her head on the nightstand and she was trying to go to sleep. In other words, a non-issue. That said, like with anything else, there will be some for which this is an annoyance - in product design that's called standard deviation. IMHO the cost/benefit to engineer the unit to silence will not pay off.