Pretty outdated review as he's on Windows XP. But still covered the hardware end of things nicely.
This dudes willing to spend $2,500 so won't be looking at the Scarletts.
PCI card seems still the way to go if you can afford it.
Look at all those old PCI cards that people are still running. They never seem to die.
I've got this old Card Deluxe PCI 2x2 with SPDIF and it's rock solid still. I've never used it much with my DAW because of the lack of in outs but I just tested it and it is way up there with my Scarlett as far as specs and performance go and it's from something like 2003.