Pros
Early retirement after 30 years in the industry! The 12 hour shifts often went by quickly. Sometimes they did not. Pay and benefits were good, especially for the long-time employees. I stuck it out as a Field Service Engineer at the same IBM NY site (with travel exceptions for about eight years) starting in 1994 with Lam Research Corp. I then moved on to GaSonics, Novellus, back to Lam, then Global Foundries and ON Semi. Electronics training is a MUST to perform the job requirements safely and effectively. I had DeVry Technical Institute electronics training and it paid off with a good job less than two weeks after graduation. My equipment manufacturer employers then sent me to months of training, mostly on the west coast, over the years which helped immensely. OJT at work is useful but having formal training on the machines you would be working on in the field was hugely helpful to get the basic knowledge needed to start. From drawings and schematics to operating systems to turning wrenches and performing maintenance were critical skill needed to be a solid maintenance tech.
Cons
Stress and frustration levels were often high. Installing, maintaining and repairing multi-million dollar semiconductor manufacturing equipment puts a lot of pressure on one's back, especially when you have a good work ethic.