Had to go do a little snooping, seems 2013 was the first model year. Engines from 365 to 430 horsepower. Seems targeted to end dumps, Concrete trucks and the like, not so much OTR.
They had some experimentals running in late 2011. McClymonds Supply & Transit out of Portersville, PA. got a couple of them. They run 500+ dumps along with 200 or so tractors pulling dump trailers so Caterpillar must have figured they would be a good lab rat. McClymonds bought hundreds of Cat powered trucks over the years so that may have helped too. I really haven't heard anything much pro or con about them. If they are good then PACCAR best figure out what to do about their junk ass MX engines or my employer is gonna lose one of our biggest customers.