I have this on my new (gen 3) iPad. I have the crystal clear (no anti-glare/fingerprint version) version on my iPhone 4S (which I assume is similar to the iPad version). I like both, but both have strengths and weaknesses.
The Ultra Optics (and make sure you get the versionfor the new iPad, and not the iPad 2) screen protector is nice, but it takes a lot of patience, really clean hands and screen, and a bit of luck to get it on right. But that's probably true of any precision cut screen protector of that size (and, unfortunately, you only get one per package). It's described as a balance between clarity and anti-glare/fingerprint, and I would say that's right. The Ultra Crystal (glossy) material is very clear, but picks up oil/fingerprints like crazy. The Utra Optics is still clear (but, face it, it's matte and therefore not as clear), but does repel or hide fingerprints/oil well. I'm happy with it, but it does make a "zip zip" sound as you run your fingers across the screen.
The Ultra Crystal material, at least when new, is super clear. You can hardly tell it's there. It's on my iPhone 4S for 7 months, and is showing its age a bit, but my iPhone is often in my pocket with coins, keys, etc., and it's done a great job protecting the screen. I would have gotten it for my iPad except that it does pick up fingerprints and oil pretty quickly, and I wanted to try something that would hide those a bit.
Unfortunately, Spigen only includes one protector per package, and it's a pretty expensive mistake if you botch the install (I've had that happen once), but the trick I've found is to have a really clean surface, really clean hands and screen, a really stable spot for the device, and patience to make sure that the first part of the device goes on straight, and then work deliberately but quickly.
Whatever you do, avoid Zagg (at least until they come out with better materials). I used one once, and it really protected the screen from what would have otherwise beena horrible scratch, but the materials feels like cr_p compared to the Spigen Ultra Crystal.
Good luck.