Hi,
I bought a 17" Speck Case for the UMBP. After reading so many positive user feedback for it, I have to say, I am quite disappointed. It certainly is not as well made as the previous one I had for an older MBP that was made by Incase. It is a bit more flimsier than the Incase version and one can tell that it cheaper quality plastic and the finish/edges are not as good either. You can tell it made by a cheapo process. On mine, one of the rear plastic tabs does not snap on and is bent back a fair bit so it sort of just flops unattached at that corner leaving a large gap for dust and dirt to get in. It is too far bent back to manipulate back to the desired position and because all tabs need to be engaged to keep the shell attached, the bottom shell just comes off very easily.
The top shell affects screen position in that it always creeps back so one ends up having to adjust regularly to keep it in desired position. I have written to Speck but am still awaiting a reply. I paid the equivalent of US $80 for two pieces of cheap, crap plastic - I could have got a really decent laptop bag for that!
I would recommend others look at Incase instead - note though that their products seem to be top notch but in my experience, their customer service was not only an absolute joke but also non-existent!
Bazzy!