Let me first preface this with what I expected from both prior to buying.
I've read a ton of reviews and watched videos. I thought the RocketFish would be the way to go. I am a fan of hard cases, and loved the clear look that the case gave the Pre. So I was excited about that. I was planning on using that and putting on a cheapo screen protector.

The Invisible Shield that I've been reading about sounded horrid. Everyone says it has this rubbery grip, and that it was a pain in the *** to install. Not to mention the price. It's a tad high. I definitely did not want my phone to give me any resistance while using the touch screen, nor did I want any discoloration in my colors.

Well, I went to Best Buy and bought them both today.
First I put on the RocketFish. Immediately I didn't like it. It was sorta a pain to install because I didn't wanna scratch my baby.
Second, The damn thing slows the speed at which I can slide it open. And it wouldn't really open all the way without a little extra push.
That, I did not like. So it took me just as long to take it off as it did to put it on. It will be returned. Sadly, it's not for me.

The Invisible Shield was/is amazing. I've never used their products before but after following the instructions to a 'T' I got it on the phone in about 30-45mins. Yea, it was a pain... and yes, it was expensive. But let me tell you.... That **** is amazing. I don't know why phones don't just come with that pre-installed. Or at least give us the option, lol.

Needless to say with a little time, patience and effort you can install the IS and will probably enjoy it just as I do. I don't really feel any resistance on the screen when using it. There are no air bubbles and there are no creaks. The corners were a ***** to install, but hey... Patience. The only gripe I have is somehow a small piece of dirt or something got under one part, I will have to try and re-apply it later.

I will be returning my RocketFish and using that money to buy the IS for the back of the phone.

Hope this helped anyone on the fence like I was. Go with the IS, you won't regret it. (Oh yea, I did the key scratch test.... simply awesome)