Well it's now been almost a year since my original post, and I would say I've been having this problem since 2011 with no solution in sight.
Have heard nothing from Apple or anyone else about this issue. Yet it still persists the exact same as ever.
I have completely scoured the internet for anything to make it work. Countless 'fixes', 'patches' and terminal commands.
Nothing works. Opening a list of 100 or so files on an SMB share using any Mac is hopelessly slow (even on the Sierra beta).
It's an important part of my work to access drives like these regularly so I've given up and will boot into Windows 10 through Boot Camp by default. Where everything works amazingly well. Even using Parallels to boot into Windows completely solves the problem.
So many friends of mine own Macs and have USB hard drives connected to their routers (this is not only a thing 'geeks' are doing by any means). Being able to access a network hard drive is something a lot of 'normal' users seem to be doing. Even they are all frustrated by how unbelievably and painfully slow it is to simply browse through their drives. One of my friends has given up and uses his iPad to Airplay content to his Apple TV because that's the only way he can browse his network drive without wanting to throw a multi-thousand dollar device at the wall.
It's unacceptable now. My laptop is starting to age now and I'm looking to buy a new computer. I've been using Macs for over 10 years now but I'm beginning to give up on them for software reasons. The hardware is incredible but macOS is becoming a disgusting behemoth. Apple seems to have no interest in fixing the most glaring bugs I see on a day to day basis. Saddens me to say but right now only Microsoft actually give a **** about shipping working, stable desktop software so I'm probably just going to go buy a Dell XPS or something and I'd be way happier than I am right now.
Windows 10 honestly runs rings around macOS at this point even on a productivity level. Window management on macOS is a mess. The confusing and completely unintuitive way that full screen apps / split screen and Mission Control all fight for your attention is utterly baffling to me. My mum accidentally went full screen into an application and literally had to phone me up because she couldn't figure out 'why the menu bar and dock have disappeared?' and she couldn't 'get out of it' (does Apple honestly think most people know that 4 finger gestures are 'intuitive' or even known about them?). On the most basic level the operating system has been steadily hollowed out from the inside and the most fundamental tenants of user experience have been gradually deformed into a completely inconsistent, confusing experience.
I've definitely come to the point where I feel like I have to fight with my Mac to get it to do what I want. Example: wanting to swap windows within an application. Something as simple as having hover-previews for all open windows of an application in the Dock (I know HyperDock exists). Windows has had this for years in their task bar and how Apple haven't thought it was a good idea to, frankly, steal this and implement it natively into OS X is beyond me. The OS X alternative is having to finely right click the dock icon of choice and then read through the multiple lines of window titles (to make it worse different tabs don't show up in these lists, even after having touted 'macOS Sierra tabs everywhere'). This is user experience 101. Even window snapping for split screen and full screen on Windows is such a better executed and dare I say user friendly idea than the obnoxiously slow, choppy, 'entering' full screen animations and nausea inducing desktop switching animations I've been tolerating on OS X for years now.
Apple's solution to this seems to be its insistence on gestures (which most of the population don't even know exist and meet them with 'What! I didn't know you could do that!', followed closely with 'Wait a second, how many fingers do what which way where?'). Using 3 and 4 finger swipes all around the place just to find a different window of an application, or to change applications, is completely exhausting as a user who wants to be productive in any way.
Literally everything window or multi-tasking related on macOS requires more clicks, swipes, reading and general concentration and time than the equivalent on Windows 10. It's a stark difference.
People I know who have had some experience using Windows 10 (or even Windows 7) after using their Macs for a couple of years have had similar comments, for the first time in years, things feel so much easier to do in Windows as opposed to macOS. It's a combination of Windows 10 actually being quite good (compared to 8 and the now ancient 7), and macOS gradually declining in user experience every year for 6 releases or so. As far as I'm concerned OS X was at its peak around Snow Leopard. On the OS level, every release since then has been a 'hey look, things are different this year, but not necessarily better for the user.' Sure there have been some nice features but the fundamentals have been messed with way too much.
To be honest, if PC's (or Windows rather) could use iMessage and receive and make phone calls from my iPhone I would be leaving my Mac behind in a heart beat. The infamous Apple 'lock in' of device compatibility has essentially blackmailed me into sticking with OS X far beyond its prime. Throw in the mess that is the Mac App Store, and in most categories, Windows has surpassed macOS.
