I can't give any first hand experiences with either of the two protectors you mentioned, but I have heard that the Invisible Shield will hinder the touch sensitivity. Check out some of the reviews on the net.
I actually went with a screen protector from PowerSupport (powersupportusa.com). I got their anti-glare model, and I have been very impressed thus far. The glare is essentially eliminated, fingerprints are significantly reduced (to the point that I do not feel the need to clean the screen at all after one complete day of use). Furthermore, there is literally no screen sensitivity lost. The screen still feels amazing (obviously a bit different with the protector), and I only notice a slight bit of "orange peel" effect.
With that said, it was a pain to get on. I placed it on for the first time and noticed two trapped pieces of dust that were causing air bubbles underneath the protector. So, I began using packing tape to lift the protector, and then using another piece of tape to lift up the piece of dust. Every time I did this, I seemed to trap more dust. All of a sudden, there were like 15-20 pieces of dust stuck to the adhesive side of the protector. I thought I was done for! But, I used the tape on the adhesive side of the protector, and it took the dust right off! I now have a flawless install, with no air bubbles present. It took me around an hour and a half to get it perfect (I had never installed a screen protector on any device before... complete noob).
Sorry if this doesn't help... just thought I'd offer my 2 cents.