I have dodged upgrading my Intel Macs to Monterey due to a variety of issues posted by many others. So I have 2 Intel Macs running macOS before Big Sur and one Mac Studio Ultra that came default with Monterey.
For me, the #1 issue with Monterey is the dreaded "unexpected ejections" of USB-connected enclosures. Some work fine, some don't. No easy way to tell which will remain connected and which won't. Others find that some hubs, some other types of USB hardware, etc is always hit or miss- some work, some don't.
I've done a ton of testing with my Studio to try to resolve the issue myself. After much effort, I conclude as much as I can without a way to definitively test it that Monterey has port bugs affecting both USB and Ethernet ports. I strongly believe that I could downgrade this Studio to a macOS BEFORE Big Sur, my own stuff not working well would return to working as they do when hooked to those Intel Macs.
In trying to resolve the problem, I've seen many posts by others who upgraded their Intel Macs to Big Sur or Monterey, crashed into these same issues and then some decided to downgrade back to their old version of macOS until Apple fixes this problem.
Thus, if I was you, I'd scratch up $50-$100 to buy an external, install Monterey on that one, boot into that one and see for yourself with your own stuff. If good, then you can much more confidently upgrade the internal macOS. If not, you can switch back to "old reliable" very easily.
Upgrading with no easy way back makes switching back- if you want to do so- very complicated. Save up the $50 or $100 and use it like insurance against this scenario. Else, maybe a friend can loan you a spare external for a few weeks so you can try before you commit.
