I've talked to some of the people at Mentor Graphics who were there during that period. The company basically went from #1 in the industry to #3 or so during the course of the C++ refactor (and the EDA industry isn't exactly big). Bjarne Stroustrup showed up at the company now and then because the company was such a major early adopter. Inheritance chains were 5 or 10 classes deep. A full build took a week. The company hosted barbecues on weekends and invited the employees' families so they could see each other.
I only worked there somewhat later, so I just heard the stories from people who were there at the time, and only after I had been there a while. Take some old-timers out to lunch now and then, you'll learn a lot. I ended up leaving, I was more than a bit frustrated by the organizational culture and the build system my team used was by far the worst I have ever seen in my entire life.
But Oregon is an awesome place to live, the salary was good, and the hours were normal.