So after the first good bit of the day dinking around with this, I've not run into anything show stopping. All the games I have recently played still run just fine, including X4. My VPN and MFA stuff still works as do all of my work related client apps, and virtualizations. So business as usual.
Some things will take some getting used to, which I'll detail below, but overall, it's Windows and they're not reinventing the wheel so if you're familiar with Windows 10, 11 likely won't be a shock to migrate to.
Bear in mind, this is based on the first dev preview release so the final GA release could be different.
Some things that have notably changed:
File explorer - gone are the copy/paste shortcuts from the right click menu. Instead they've been moved to the top bar and into a static menu if you right click and then click "show more options", which will bring up the same right click menu that's present in Windows 10. Along with that, the ribbon has been removed completely and the top portion of file explorer is dedicated completely to file management and sorting options.
If you don't use keyboard shortcuts for copy/paste and such, I can see having quick access to them at the top of file explorer enabling you to perform those tasks slightly faster, but you will have to retrain yourself to use them.
The Start menu - There's plenty of pictures of the start menu out there and there's not a whole lot you can do to it, other than move the taskbar alignment to the left or center, which does move the start menu with it. The bug I mentioned in a previous post about not being able to pin items did resolve itself after a reboot so I can pin w/e I want to it. Tbh, I did get rather used to grouping apps in the start menu in Windows 10 and I had a layout I liked. I'm fine with the smaller icons in Windows 11 start menu, but perhaps there's an opportunity to optionally use grouping with the pinned stuff on the start menu.
The start menu doesn't grow if you pin a bunch of stuff to it. It seems to have a static height/width relative to the position of the start button. Instead, if you add a bunch of stuff it'll create additional pages to scroll through. Though pinning everything you install is likely unnecessary as there is still the "all apps" sub menu that lists everything alphabetically as it is in Windows 10.
Settings - lotta changes to settings but they've made it less cumbersome to navigate and have more logically grouped things together. Not gonna go over much of this in detail since most folks won't likely be spending a lot of time in there, but I will say it's snappy and easier to find what you're looking for.
Snapping - this is a feature I was looking forward to and I gotta say it's pretty neat. Hover your mouse over the maximize button on any app and it'll bring up predefined layouts that will fit whichever monitor dimensions you're using the app on and will highlight each section of the divided up window to pick an app to fit to it. But it doesn't stop there. Each of the horizontal and vertical boundaries created can be moused over and drug to dynamically resize apps on either side of it to meet your needs. As was mentioned in the unveiling announcement, all of those apps you've snapped are grouped together in the task bar so if you minimize any or all of them, you can hover over any of those applications and the grouping will be there next to the preview thumbnail and can restore them all back to the way you had them positioned.
For now, in conclusion, my experience has been fine thus far, minus one bug where the taskbar icons aren't populating on my other monitors despite that being enabled. I'll peruse the android app offerings in the coming days, if there's any in there I might be interested in running, just to see how that plays out. Everything seems stable, however, and feels faster... not that Windows 10 was at all slow for me, and it does look a bit nicer, to me at any rate. I'll be interested to see where this goes over the next few months.