Actually, unless you're throwing the case in directly with something like your keys, I've found the PS Clear Air Jacket is pretty damn tough to scratch. While I do think the price is overly high, I can't say I'm at all disappointed in the performance as far as scratching goes. Mine looks as nice as it did three months ago when I put it on.
I suppose if you're constantly exposing it to sand or grit, there could be an issue, but at that point, any case is going to scratch. Mine slides in and out of a leather pouch regularly, gets dragged across tables and nightstands, shoved into my jeans, and occasionally gets thrown in my purse without other protection--no visible scratches. I take some reasonable care with it, but not a lot. Not sure how others are managing to make a mess out of them.
What I don't like--not the easiest case to remove, so if you swap SIMs regularly, forget it. It has very little flex and I have a small bit of crackling on an inside edge from putting it on and taking it off too many times. It's not very noticeable, but it's there. Mine also had a sharp point on one edge (and that edge overall is sharper feeling than the other side). A few quick rasps with a jewelers' size diamond file took care of the point, but that shouldn't've been necessary for the price. (Not sure if that's a common issue though as I've never seen it mentioned elsewhere. Mine is also the Japanese model, picked up through Amazon at a discount versus the US one.)
All in all though, I'd buy another one in a heartbeat. It's great for displaying my printed DecalGirl skin and protecting the back of my phone--and it doesnt stain the way every frosted or colored "soft touch" case I've had did, or scratch the way other clear ones seem to. I just wouldn't remove it again once it was on to avoid the potential for cracking the inner edges the way I did with this one.