I spoke with old timers at Cray and they were all shocked by the laxs work ethic at SGI: people coming back from months of paid vacation and not being sure it they worked there anymore.
From the Cray culture (and some of the Cray employees) we got the IRIX release train, where we'd ship a new QA'd release every quarter. If a feature wasn't ready it just got pushed out to the next release, no big deal (sometimes this didn't work out; bizarrely one of the biggest screwups came from the CXFS guys who were working in the old Cray campus in Eagan, MN).
[1]: Though as I read Zero to One it's interesting to see Theil's perspective on process-vs-product outlook. Definitely the product-driven SGI was the more optimistic one.