>I haven't even tried 10.12. The previous releases (10.9 through 10.11) have thoroughly butchered the interface, usability, compatibility, performance, and UNIX-level features.

Anything specific? Because I don't find anything "butchered", apart from the usual assortment of bugs.

Multi-monitor support got pretty effed up around 10.7 or 10.8. It had something to do with the new full screen app mode.

It seems like 10.6 is the agreed-upon high point for macOS - then the porting of iOS designs/features (remember those linen textures?) resulted in more UX issues and bugs than usual. Thankfully it has improved significantly since then, though.

> It seems like 10.6 is the agreed-upon high point for macOS

I don't know who is agreeing here, but I find people who say this to be looking with some seriously rose-tinted glasses. Mac OS X 10.6 is really not that great. It's hardly as "rock-solid" as people make it out to be.

It's the iOS 6 of OS X. It's the refinement of the most familiar interface before things started changing. That doesn't make it better, just more comfortable for some.

Here's the kicker: it's ugly. It looked good at the time, but looking back on it, it looks clunky. The remaining Aqua elements look out of place and weird, buttons lack consistency, design is all over the map.

10.12 isn't perfect but it's a pretty damn good OS. Mac OS X/OS X/macOS has always been kinda buggy; it's the nature of an OS with a significantly smaller userbase. IMO it's no worse now than it was in 10.6, except it has a ton more features.

> IMO it's no worse now than it was in 10.6, except it has a ton more features.

Many of those features are the reasons why it is worse to many people. New code comes with a cost. Every new system feature (handoff, clipboard sharing, sandboxing, etc.) is more places for bugs to pop up.

There was no code in 10.6 that could cause your desktop, documents folder, and photo library to just randomly "disappear" one day when iCloud decides to have a few too many drinks and stumbles home. In 10.6, they didn't need a new low-level networking library to support drag-and-drop between your iPhone and your Mac, and as such, that code wasn't there to repeatedly rename your Mac "Foo (7)" or whatever.

Sure, if you use the new features, then on balance, they're probably fine, despite the problems that pop up. But a lot of people see these features as solving problems they don't have and solving them in a way that makes loads of things that used to work reliably no longer quite so reliable.

> In 10.6, they didn't need a new low-level networking library to support drag-and-drop between your iPhone and your Mac, and as such, that code wasn't there to repeatedly rename your Mac "Foo (7)" or whatever.

What are you talking about? Assuming you mean universal clipboard (you can't drag & drop to your iPhone), that's built on top of handoff, a technology we've had for a few years now, and has nothing at all to do with your computer being named "Foo (7)". I suspect you're thinking of the discoveryd fiasco, which isn't related to any feature work at all but was caused by Stuart Cheshire retiring (and was fixed by Stuart coming back out of retirement).

If by "effed up" you mean it now works in a way that is actually really useful. Previously, all monitors shared a single space, so you couldn't switch between spaces on one monitor without switching your others. Now all monitors have independent spaces, so you can switch spaces separately, and you can fullscreen an app on one monitor without affecting another. It's soooo much better now.

>Multi-monitor support got pretty effed up around 10.7 or 10.8. It had something to do with the new full screen app mode.

Might be -- I'm using just one external monitor, so don't know.

That said "multi-monitor support suffered badly for a version or so" is rather anti-climatic after "butchered".

I find that the multi monitor support greatly improved when going from ElCap to Sierra.

I stuck with snow leopard for years. Am pretty happy on mavericks now on my 2008 MacBook.