Very little. Yes, they finally made a Mac Pro that is extensible and up to date. Basically everything the 2008 Mac Pro already was. On the downside, they doubled its price so for the non-Hollywood customer, there still isn't a desktop machine. Even 3k is much for a deskop machine, but I had set some money aside to get a Mac Pro, if it had started around its predecessor price. There was even a time in the past, when a Mac Pro would start below 2k and consequently was very popular.
> on the downside, they doubled its price so for the non-Hollywood customer, there still isn't a desktop machine. Even 3k is much for a deskop machine
I think there were more benefits to an ordinary user to getting a tower in the past then there are now.
In the past even a hobby or prosumer photographer would see a big benefit from getting a Mac Pro. Nowadays an iMac or Macbook Pro with very normal specs can edit large RAW files without breaking a sweat.
The extra HDD bays on a Mac Pro were great because you didn't have to mess around with USB2 (cheap but slow) or FW (fast but expensive). Now you have USB3 (cheap and fast) or TB (very fast but expensive).
I guess that leaves upgradeable graphics cards, at this point it is easier to just get a PC or try a hackintosh build if you want a beast GPU for the latest games.
> There was even a time in the past, when a Mac Pro would start below 2k and consequently was very popular.
2006:
Mac Pro base model:
$2,199 ($2,800 in 2019 dollars)
Internal storage is a huge thing. I have external storage attached to my 27" iMac, but it is not completely reliable (disks get ejected occasionally) and completely beats the purpose of an elegant desktop machine. So I really would like a machine with several drive spaces, especially if I can access them. I could have lived reasonably by upgrading the internal storage of my iMac, if there was any way for me to access it.
Graphics cards is another thing, but also the plain ability to clean fans when they start to clog up. The limitations of the iMac are amplified by Apple making the interior inaccessible.
Finally, while the screen of the iMac is great, I would like to have a larger screen.
So there are plenty of reasons still to have a bit more than the iMac can deliver.
I've had BlackMagic 1U SSD rack with a few drives connected to my 2013 iMac 27'' via Thunderbolt since like... 2013, and not a single time did they disconnect. It just works.
The rack is under the table so it doesn't "beat the purpose of an elegant desktop machine" either.
Lucky for you that you had no disconnects. But getting those limits which files you can put on the external disk if you need them available all the time. E.g. when my external disk gets disconnected, EyeTV stops working as its work directory is no longer existant.
Also, I don't see how having an additional large box (which by itself costs as much as many PCs) doesn't defeat the purpose of an all-in-one machine.
I am not arguing that the iMac shouldn't exist, I just listed a few points which can be better addressed with a proper desktop machine. Why I would be willing to spend quite a bit of money for that convenience.
Maybe check your power supply? I've supported Macs for a couple of decades and normally people have storage mounted for years without this kind of thing happening in the absence of some sort of hardware or environmental problem.