Pros
There are very competent and able engineers working at KLA-Tencor, most of which have a passion for designing and engineering quality products. If you work for the right group, you can almost bear all the negatives I'm sure other people have written about in their reviews (which are all pretty accurate).
Cons
Coming from a mechanical engineer: The management is very politically driven, motivated by the $$$ and deadlines/pressure from the upper echelons, not with whether a product is ready for production. Is this just how business is run these days? There is so much red tape / paperwork to do! Although my job title says "design engineer", design only constitutes about 25% of my actual workload. The other 75% is filling out forms and pushing papers in a bloated and inefficient system in order to get anything released for manufacturing.