If you bought a PSP go, you need PSP go cases. The smaller size was probably a big factor. While the other PSP models were certainly portable, they weren't always as pocketable, especially if you used those near-indestructible (and pocket-hogging) Logitech PlayGear Pocket cases. When I got my PSPgo, I wanted a PSP go cases that could protect the screen from other objects in my pocket (since the PSPgo was small enough to allow it), yet small enough so as to keep the PSPgo's smaller form factor in the first place. After reading and watching reviews of the other PSP go cases, I'm confident that this PSP go cases suit my needs perfectly and may even be the best case for the system, period.
The PSP go cases are just two pieces of silicone that snap on quite snugly. The top part does not wiggle at all, which is great because I didn't want any particles sneaking in and causing scratches if the screen wiggled. I didn't notice any difference in screen clarity either. There are holes cut out so you can still hear the speakers and access the PS button.
While it is true that you might get a few dust particles in between the screen and the top case, take comfort in the fact that you can always take off the PSP go cases and try again. Alternatively, you could find a Zagg cart at your local mall and pay $30 or so for the screen and perfect installation, but it is just a screen (not a case), and remember, this PSP go cases was much lower price with free shipping worldwide!