I bought the Clevo 730SU from Xotic PC without an OS (it is the same model as the System76 Galago, but I was putting Arch on it anyway and didn't care). I knew I'd have to buy a replacement NIC because it came with some junk realtek one (I always buy Atheros AR9452s from Ebay because they are cheap and good, they get a good 30MB/s bandwidth for me and good bluetooth for like $12). Got a Crucial m550 ssd to pair with it, and was thinking of doing FHD on both drives, turns out the Hitachi drive it came with didn't support it and the Crucial drive only used bitlocker rather than ATA passwords so I just used luks on the mechanical and my home directory partition and kept the base system unencrypted so I don't have to do any early boot password nonsense.
I also have a workstation, a 4770k on an Asus z87i deluxe with a (now) MSI 290 GPU, a Samsung 840 Pro SSD, and another one of those Atheros NICs.
Both machines run Arch, and I do all my development work on them. I can't stand the OSX UI anymore, and I do hobbyist KDE development work.
So hardware woes:
As per usual, there is no motherboard vendor that "supports" Linux. So you are blindly throwing darts on good EFI implementations, of which there is one, and its called Tianocore and nobody uses it because they are all dumb. So in my time I have gone through three motherboard vendors, Asrock, ASUS, and MSI, and I have only ever had a flawless experience on the MSI board. The Asrock board wipes its EFI boot table every update, and the ASUS board has so many problems its insane. It only accepts one EFI boot entry, the integrated GPU cannot PRIME as a secondary card because of EFI breakage, it doesn't report temperature sensors right, for the longest time it just randomly overvolted or undervoled the vcore because it has an onboard custom vrm controller, and the interface is shit and the update procedure requires you to put the firmware blob on a fat32 usb and install it from there. The Asrock board had DHCP support so it could just update over the Internet. They are all shit, because I shouldn't need to do any of this crap and should just have my kernel as a coreboot payload if the world made any sense.
I should mention I also had an "old" workstation using a 920 and gtx 285, which was originally running Windows Vista before I saw the light. For a while the Nvidia driver worked ok on there, but suspend broke it and it couldn't resume the video device, and when I eventually gave that workstation to my mother (who reads email on it now) Nouveau worked flawlessly and was able to resume and do dvi -> hdmi audio perfectly out of the box.
Otherwise I had a 7870 I just gave to a friend for Xmas when I first built my workstation, and like I said I replaced it with a 290 now that the card has good radeonSI support. That thing worked pretty flawlessly, and if I ran PRIME from the integrated to the discrete it was a great multi-gpu experience and worked flawlessly.
The only problems I've ever had with my workstation are that since I run btrfs on it, I've had the file system become corrupted and unrecoverable three times, and I was able to recover it two more times. I always keep weekly backups of the disk (its a 256GB SSD paired with a 3TB internal HDD and two 1TB externals for backups plus Spideroak) so I just do weekly images and reimage whenever the filesystem dies. My general policy is once I go six months without it failing catastrophically I can start recommending it to everyone else.