I grabbed the clear crystal film first, and used it for several weeks. But I got to wondering if the glare when I used the phone outside could be reduced with the matte film, also included. It was indeed more matte, but after a few weeks I found that the matte film felt and looked just a little thicker and a little less smooth, especially when using sliding touch gestures (like unlocking the phone). So I went back to the crystal film.
Mini-Review: The films are tough and protective, and after 5 months of use I'm just starting to get a few almost-invisible scratches and scuffs. It’s easy to keep them clean, and if this stuff isn’t as oleophobic as the 3GS screen, it comes close. Unless you’re eating fish and chips, it’s easy to wipe off minor finger grease on any soft cloth. FWIW, I’ve almost never used a case that covers my screen, and I keep the phone in my pants pocket. I don’t put keys or coins in that pocket, though, and when I set the phone on a desk or the car’s cubby, I try to keep it face up. I do drop it occasionally, but not too hard!!! I would have to give these films a 5-star rating for functionality and toughness. (I haven't tested their mirror film, and their website says they have a privacy film coming soon.)
Mini-Tutorial: This brings us to a few hints and tips for using this product. Putting the film on a brand new clean phone in a clean environment is a piece of cake. You can partially apply the film, check the alignment, and re-lift and re-locate if needed. I like to align the long edge of the film first, lower it to check that the holes for the receiver (phone) and home button align well, realign if needed, and then lower into place. The film is thick enough never to wrinkle, tough enough to rub down vigorously, and it adheres via simple cling, meaning it is neither going to slip around nor leave an adhesive around the edges (or on removal).
But the strengths of this product are hidden a bit in the way you can change films and troubleshoot air bubbles and the dreaded dust motes if your phone isn’t pristine, or when you change films. It turns out it’s easy to lift the film off using a piece of ‘invisible’ type clear tape, like Scotch brand invisible tape. Don’t just claw at the edges with your fingernails, as this may permanently deform the edge just a bit. And do lift the tape off the film gently when you’re done.
As for bubbles and dust, Power Support has a nice video that shows how to deal with isolated bubbles or dust. (Dust is usually the culprit in bubbles you can’t wipe away). The essence of removing a bit of dust is the use of a second piece of invisible-style tape, in what we might call the tape-tap method. I like to lift the nearest corner using tape 1, then insert tape 2 adhesive-side up, and just touch it lightly to the film in the area where the dust is sitting. Since most of the film is adhered to the phone, tape 2 pulls off easily. As they note in the video caption, the only trick is not to touch the adhesive side of the film or the screen with your fingers.
Finally, I found two more hints for changing or cleaning films. First, change the film in a closed bathroom after you run the shower for just a couple of minutes (don’t turn the place into a steam bath). I like to put the phone down on a clean towel, well away from the sink, and polish the screen with the black lint-free cloth Apple supplies. (Any sunglass or optical shop has equivalent cloths for sale).
If you already have more than few dust motes stuck under your film, and especially if it looks like you recycled a piece of wrapping tape, the simple tape-tap method may be inadequate. But don’t despair. Again I favor a humid, closed bathroom. Clean the phone's screen with the lint-free cloth and a drop of optical cleaner (household window cleaner will work if you polish away 100% of the residue, or get some from your sunglass or optical shop). Next, wash the dusty film under the tap with a drop of clear liquid soap or dish detergent between your palms. Rinse very thoroughly, getting your hands clean in the process, dry your hands, and tap the edge of the film on a clean towel a few times to shake off all but the smallest water droplets. Now move over to where the phone has been sitting away from any splashes. Align the film, apply half way to check the alignment, and ease into place. At this point the water droplets form a film that disappears as you rub with your lint-free cloth, and most or all of the dust should be gone. The tape-tap method can be used for any dust that remains.