Build 1909 vs. 1503?

Hi! Hope you’re doing well!
Recently my computer updated to 1909…it was a sticky situation, had to do a safe mode login but luckily after that it worked!
Now, I’ve noticed quite long startup times, but it seems much faster (than before) afterwards. To me this seems like a valuable trade-off.
In startup options, I noticed the option to uninstall updates (and there’s also a Windows.old on the root of my drive)
Now I think making more changes could add room for error, but are there any other reasons to stick with 1503? Maybe any personal experiences you guys have had?
I did lose my custom theme but I could reinstall it if I really wanted to. Been enjoying it just as is for now though.

Thank you for your input!