Pittsburgh is probably really close to ideal. I can't really think of much of a downside.
It has a lot of universities, and the programmers are quite good (the ex-CTO of Modcloth? had a video where he pointed out that the Pittsburgh office was quite a bit better than the SV office). Your factory workers will be out toward the airport and your knowledge workers will be downtown. It's a very old city, so it is quite a bit more pedestrian friendly than most. And, because it's old, it has a really good arts scene. And Pittsburgh has a woefully underutilized airport.
The only downsides are weather: 1) Lack of sunlight--Pittsburgh is almost as bad as Seattle in that respect and 2) Winter--Northeast winters SUCK.
And really, Pittsburgh is fantastic. Good schools, good commute even if you live in a suburb, great food and alcohol scene, with an arts scene and history to rival any major city (Carnegie and Warhol for starters).
1. Beautiful, unique geography, with a ton of outdoor stuff to do (granted, at least in summer). 2. Gorgeous architecture all around. 3. Great public transportation. 4. Lively nightlife, lots of options. 5. Relatively cheap
Pittsburgh basically has infrastructure for a city twice as big, but has managed to transition from its industrial past better than most rust belt cities.