I don't own a Mac Studio, but was considering it at one point. From my research, and what I have been following on the forum and elsewhere, here are some potential issues for the Studio:
1. Fan noise - not what you typically would hear with most fan noise, but like a whistle or tone. Not all people hear it on their machines. Another thing that is weird is that some people can hear the noise, and some people cannot on the same machine, so I wonder if it is maybe a frequency that most people's ears cannot register. Not sure. This didn't bother me, as I have a lot of hearing loss from my time in the military.
2. 10G Ethernet issue - this isn't just on the Studio, but a lot of Macs. I have seen two issues reported lately, and it seems to only affect the 10G Ethernet port on Macs from the last few years. One being that AirPlay doesn't always work from the device with the 10G Ethernet. The other is that some people were finding that the 10G Ethernet was dropping the link speed of their connection to 100Mbps when connected to a 1000Gbps network.
3. GPU scaling - as the number of GPU cores goes up, the scaling gets dramatically worse. I have seen it reported that this was a problem with all the M1 chips, a design flaw that was missed during the development, and it might be the reason why there wasn't an Mac Pro already with the original rumors of up to 128 GPU Cores as this would have really shined a light on the design flaw. The issue was reportedly corrected, or at least reduced for the M2 and up chips.
There might be some others that I cannot remember or didn't see.
Another thing you might want to consider is the HW differences between the Mac Minis and the Studio, as there are some improvements over the Studio on the M2 Mac Mini.
I have tried several M1, M2 and M2 Pro Mini but I cannot find one without issues such as wifi, bluetooth and audio.
I know this isn't what you are asking in the thread, but I am curious, have you ruled out your equipment you are using with your Mac Minis?
I don't use Bluetooth on my two Mac Minis, M1 and M2 Pro, but I use Wifi on both of them, and haven't noticed an issue. Maybe I am just lucky or you are really unlucky.
Another thing, if you otherwise like everything about your Mac Minis, but are having Wifi and Bluetooth issues, why not just use Ethernet or some other networking solution, and a USB Bluetooth adapter?
Maybe just replacing one of these things might help the other.