[LunarBerry]

My girl has the cotton coat, but it's very shiny and soft. It grows like a friggin weed >_< lol If I let it out of control she looks "fat/fluffy", it's fairly thick, too. You're blessed if you got a silk coat but grows fast, as I hear the silk coats takes more time.
The problem with having such long hair in any hair type, is the maintenance. If you're going for that very or fairly long "show coat", you'll have to keep the hair wrapped up when not "showing" or it'll tangle or get messed up easily. It's lots more work the longer it is. I just keep my girl's body hair no longer than a certain length (which is on the short side), but try to grow the top long for a tie or knot (I'm currently debating on this as she seems to not be comfortable with this.. she got the itches >_<) So honestly, I'd say unless she's a show dog, go with what's more comfortable for her.