The only times I've had gear fail on the trail was from seams, so I count good seams very highly when I consider new gear. Besides, Arcteryx is definitely using good face fabrics, even if their membrane is the same as another Gore-Tex piece.
This is definitely marketing, so take it with a grain of salt, but here's an example:
The newer shells use N80p-X fabric, which is good stuff. I don't know of any other companies that use such a high quality Gore laminate. After doing some research, I would classify my opinions in the following way:
Arcteryx definitely sells their brand. They sell a concept, and a style, and they jack up prices to match. They are not the end-all, be-all of outdoors gear. They are only marginally better than everyone else, and equal to or worse than some.
However, many individual Arcteryx pieces appear to be, and are reviewed as, substantially well made garments with great durability records and a performance record over time that usually surpasses their intended use or lifetime and is consistent with a good backpacking investment.
And now THAT being said, I think if I were to have unlimited $$$ for gear right this minute, I would NOT buy an Arcteryx shell since the delamination is such an issue. I believe delamination is inevitable in ANY rain shell, so you might as well spend $150 and not $650.
I would, however, buy a technical softshell jacket, something for serious winter use.