I am in two minds about it.
- I am really unhappy with Apple's recent releases, they're terrible in terms of usability and reliability. So I don't want to use them.
- I am really unhappy with Apple's recent releases, they're terrible in terms of usability and reliability. So I must use them to get to grips with the problems that is caused by them.
Several customers of mine reported problems exporting images, to which I couldn't reproduce on a test machine. Baffled me for a long time, finally after accidentally leaving the machine running for two weeks, the problem started to occur. Restart the machine and it goes away, only to come back over time. I replaced an entire section of code using alternative API and (touch wood) it seems to be fixed for the moment.
Another problem I found that required actual usage of said operating systems was using Apple's atomic saving functions, it's not documented anywhere that on recent releases it leaves behind a empty folder, after a couple of weeks of usage, it'd created the maximum number of folders (in the hidden location) and thus, stopped working, preventing my application from being able to save!. Sure enough a restart fixes this (as the OS then flushes all these empty folders), once I realized, my application cleans up after the OS.
A third problem that I only understood when using a recent OS release was a change to the Automatic termination behavior. Instead of waiting for memory pressure to get high and terminating my app (as it supports resume and is marked as can be terminated). The OS would terminate it, the moment the user switched to another application. I only realized this when I found a bunch of apps I use start behaving like this. Have now disabled this feature for my apps.
People complaining that my app was making low resolution versions of their photos. Nope, t'was a change in Apple's Photos to only use low resolution images via Drag & Drop.
So there, as much as it pains me to say it, I would actually recommend using the latest OS version. As a bonus you'll get to experience things like how a user is now meant to customize Notification preferences for your application (hint: it's not in the app).