Might be just me, I hate InvisibleSheild.
I put it on my N900 and took it off the next day.
However, if you need to perfectly conform to the curveof the glass, that's probably the only choice.
It's basically the same thing that make the invisible bra on my Mazda MX-5 Miata.

The problem is the orange peel look and feel. Upon closer look, you will see it's not actually smooth, like orange peel. And it doesn't feel smooth either, you will feel some resistance when swiping on it.

Now, I only use those $1 one or $2 for 3 from ebay shipped from Hong Kong or China. Perfectly smooth and feel good. Cheap and can replace it often. Yes, they are not soft, so it will not conform to the edge.

The one I have doesn't cover all the way to the left and right end (it can't because of the curve of all 4 sides). It extends to the end of the top and bottom, but you can see it doesn't stick to the screen at both ends. It isn't a big deal to me, it gives me perfect smooth feeling. When I put on another one next time, I will trim top and bottom a little. With the OEM case, actually, the edge of the screen won't get scratched easily as they are below the case edge.