Yes, I love the look of the QS. My complaint was that when I dropped in a 1.8Ghz Dual processor CPU, three video cards, a PCI SATA card, a FW400/800/USB 2.0 card, four large SATA drives and a second DVD drive, the Mac had insufficient cooling. Everything I did to rectify that did nothing. The Mac would consistently lock up after 15mins to an hour due to overheating. But I wasn't going to run it with the door down.
I am aware of the Windtunnel nature of the MDD, but I have to believe that Apple did a better job with internal cooling. And there are aftermarket PSUs that are much quieter. I've just never owned that Mac model.
I went to the G5 because it had everything stock that I was trying to do via customization to the QS. It even handled my video cards. All without heat issues. But yeah, I've never been a fan of the looks of this Mac. I couldn't afford a MP until 2020 when a 4,1 came into my $250 price range.
As you know, I've had one
since 2020. I also had a dual 800 Quicksilver for some time concurrently before selling it (alongside almost all of my other PPC desktops) a couple of years ago. In my experience, the MDD was actually quieter than the QS by a wide margin because 20 minutes after the latter powered on its fans would always constantly roar no matter what you were doing, even after waking from sleep. Whether there was some type of issue with mine or it being a quirk of the dual 800s, I'm not sure, but even when I upgraded my MDD in 2021 with dual 1.42s and a copper heatsink, its fans never revved higher than a small amount based on load. On a side note, I later downgraded back to the single 1.25 as the dual 1.42s would occasionally lock up due to overheating, similarly to your QS.
I can also attest that the thermal engineering of the MDD was in fact better than its predecessors, with some caveats. The airflow through the processor is indeed much improved, and drives are cooled more effectively as well (if that was ever an issue). But the airflow through the PCI bay and GPU is actually worse than the QS because the two small PSU intake fans, the only things cooling both the cards and the elongated PSU, are mounted forward-parallel to the PCI bay rather than directly perpendicular as before. So while this does provide some method for hot air to escape the area rather than collect in one place, the design was about as effective as attempting to evacuate the vast amounts of heat that the G4 chips produced in the QS through the PSU mounted parallel right next to it, especially when you are taxing the GPU for prolonged periods of time.
To make matters worse, the PSU fans depend on being fed cool air from the case inlet fan mounted on the side door... on the opposite end of the chassis. In order to make this labyrinthine design work, Apple cut out an air channel across the optical drive cage for air to flow through and be sucked in by the PSU fans above, but this is hampered greatly when an additional optical drive has been installed in the lower bay. Which means the PSU fans alone are responsible for passively evacuating air from the PCI bay on top of cooling the already hot PSU with... more hot air from the PCI bay generated by both the cards and the PSU housing. This is almost certainly the predominant reason why so many of them failed over the years because their capacitors were constantly thermally stressed beyond their limits. And yes, the PCI brackets are perforated to allow access to outside air, but in practice this isn't nearly enough when your Radeon 9000 Pro is hitting 80C+ just from rendering a simple game because it has no other way to cool itself besides passively.
But all of that being said, if you replace the PSU fans with newer ones that can silently move a greater volume of air and also install a PCI fan to help cool the GPU if it isn't already actively-cooled, most of its issues get resolved and the MDD becomes an overall much more solidly-built system with many design improvements over the QS, including a front-mounted headphone jack, far more robust door latch (the door on my QS would always fall down, the MDD closes shut with a satisfying thud), significantly better ATX PSU compatibility, DDR support, and all the other spec upgrades and resulting perks as well, such as native support for both OS 9 and 10.5. So despite these shortcomings, it is probably therefore my favorite PPC system tied with the DC G5 as they are both the best of their respective eras.
Appearance-wise, whether it's edged out by the QS or the iMac G4, it is also objectively in the top three most beautiful computers regardless of who you ask:
The aforementioned usability improvements make it even sexier, in my opinion...
More photos (NSFW):
