From the time v3 was first released, it has been stable for me and–probably–most customers. I can say “most customers” with confidence, because if the software wasn’t stable for most customers, these forums would be filled with posts about their issues.
There are customers who experience crashes, freezes, or other adverse issues. Most of these can be traced to an overreaching antivirus or incorrect cloud service settings or a wonky install or–believe it or not–outdated video drivers. Note that these issues are all device dependent–they have nothing to do with the Scrivener software itself and everything to do with the PC it’s running on.
This thread and this one are the only active ones on the forums I’m aware of where customers are having issues that have not yet been resolved.
All that to say, Windows Scrivener v3 is stable for most; a small number have issues, most of which are fixable.
If your PC doesn’t have one of the issues mentioned above, then you should be fine. Try it and find out. That’s probably the only way to answer your question. 
Best,
Jim