Hi!
I want to share my own opinion about Zagg InvisibleSHIELD for N900.

Personally I have liked it very very much.. it gives me a nice grip.
I find grip feature pretty much essential to me.. because I have usually very dry hands.

I have already dropped N900 on the second floor to the concrete ground floor ...SMASH! bit of plastic debris came out and metal frame bended a very little on the one corner.. but it is nothing that shows and everything still works perfectly.. thank god!)

I sketch and paint a lot with MyPaint application.
MyPaint uses N900 Pressure Sensitivity and I have not noticed any side-effects about pressure, it is actually works nicely.

ZAGG Shield gives me nice friction and soft feel when I draw. I like the feature, but this is personal. (I do not like Wacom pens basic plastic nibs either which are very slippery when drawing on tablets. I prefer Felt pen nibs when I working with Cintiq.)

Tone