We have a spot where we tend to dump cedar chips, because they take longer to decompose and although we don't worry about a few around our growies because we are surrounded by big cedars, we figure our growies will be happier with alternatives. But we have a "path" up a hill in our back field that turns into a mud-hole in the winter but that we have to use anyway. I've been dumping cedar chips on it for years and they decompose/get pushed into the mud/get grass growing over them just fine. It just takes a little longer, and in that location, longer is better. So I'm happy to have mixed chips, even happier if there's something green mixed in to get it to heat up a little, but I'll take any chips that come from non-sprayed land which is mostly what we get locally anyway, and if I want it to decompose faster, I'll mix veggie scraps in, use it as a burial mound, rotate it through our duck shelter, or frequently, all of the above!
I also know that a pile of pure grey pine chips I had never really broke down. After being piled for 10 months and kept continuously wet the chips looked just like the day they were dumped.