Don't own it but almost purchased one a few months ago. I decided against it due to the dirt issue. For the price, I'd rather get real leather. It's a beautiful bag, though.
I have the PM and I love it! I've had it since Nov. and I haven't had any problems with it getting dirty. I don't use it a ton and I baby my bags. You could probably get a spray on protectant for it though if you are worried about dirt.