Northwestern’s co-op is very well-established. The participation rate is 55% but if you exclude the freshmen population (because they have near zero participation rate by default), the rate is more like 80%.
http://www.nap.edu/read/18184/chapter/14
While the pay-rate is all over the map depending on the employers for NEU (unpaid is allowed though probably more for non-engineering type), Northwestern gives out guidelines to employers on their co-op website (60% of entry-level FT engineer to start and 80-85% by the 4th work period).
http://ceed.asee.org/coop_past_winners.html shows past winners of co-op student of the year and Northwestern has 2 winners in the past (tied for most with GA Tech).