I've had a few ZAGGSkins in my day and I usually buy one for every phone I get with a different design on each.
The general feel I've had with them is rather good and to be honest the only downside is they can peel in rounded areas if not applied properly. So keep that in mind when you do go to apply it.
But overall, I would definitely recommend getting a custom ZAGGSkin because for one it makes the phone significantly more grippier so one handed typing is more plausible, the skin is a custom design of your choice and its pretty much unscratchable!
So, get one!! And if you need help creating a design, let me know and I'll see if I can stitch something together for you.