Some units were buggy at launch, clearly. Most weren't. I bought one day one, and still have it; it's been fine the whole time. And yes, it didn't have split screen at launch -- no Android tablet did until Android 7, so that's not some special failing of the Pixel C.
Ars Technica has a good summary in their "One year later" review of the Pixel C. The reviewer is on his 3rd Pixel C due to hardware failures. http://arstechnica.com/gadgets/2016/09/one-year-later-can-an...