Only time will tell. The chips on the mainboard appear to be heat sinked to the large metal shield covering a lot of the board, so Uniden seems to have considered the heat issue. No problems so far though, even when running the SDS100 in a hot vehicle.
Jon, you had the SDS100 disassembled, and perhaps also will crack open some in the future. Then take a look at the el-lyt capacitors for a temperature marking. That will tell if Uniden have spent the extra money to put high temperature components in the SDS100 or if they use the standard, less expensive alternative that will have a shorter life span.
I was interested in the construction of the selector knob. My knob wobbled on the shaft to the point pushing down to enable volume adjust required much force. I pushed at right angle to the knob to reduce wobble. I was concerned it was a bent shaft. I'm now suspecting knob was canted when installed.
You pictures show what I believe to be robust construction.
The display puts out a lot of heat if you keep it on full time while on external power (like me.) And the SDR tuner and associated CPUs generate more heat than previous scanners. For me, the display is the warmest part / area of the radio, followed by the upper rear / antenna connector. The radio is noticeably warm, but not as warm as my notebook computer, LCD TV, stereo receiver, etc. Devices that consume *a lot* of power will need to dissipate a proportionally greater amount of heat - no getting around physics.
I for one welcome the warmth of the radio. I suffer from diabetic neuropathy (nerve damage) in my hands, thus to me, they always feel cold, no matter what the season is. Now I have a handy "hand warmer" whenever I need to warm up the hands. Yeah, I'm weird like that. LOL!!