I'll add my endorsement of the IQ Shield. That's what I've ended up using (for now). For a wet-install urethane film, it dries remarkably clear and glossy. It doesn't look and feel 100% like glass, but it's very close. Out of tempered glass, PET film or wet-install urethane-type film, the urethane film would normally be my least favorite, but if you want something to cover all/most of the iPhone 6 (Plus) screen, right now there aren't many other options.
There are some cons though. Performing a good installation is hard. I removed everything (towels, toilet tissue, etc.) from my bathroom, ran an air scrubber for 2 hours before running the shower, cleaning everything off with a dust-destroyer and then doing the install. I still got a couple of small specs of dust under the screen (and they're impossible to get rid of). But they're small and I can live with them for now.
These films have great adhesion to aluminum or plastic, but they really don't want to stick to smooth glass. And they really, really don't want to stick to curved smooth glass. If you use this without a case, the edges and corners will snag every time your phone goes in or out of your pocket. You'll have a couple of days max before the edges start lifting. And once they start lifting, they'll get dust and lint on them and then lift even more :-( I don't think you're likely to have long term success with this screen protector unless you use a case. If you do use a case, I'd recommend very carefully trimming the screen protector with a sharp knife or scissors (before installing), so that you leave a fraction of a mm gap between the edge of the protector and the case. The gap can be small enough that you won't notice it, but without some gap, a case with a lip will almost instantly push up the screen protector at the edges and corners again.
Trimmed, and used with a case to protect the edges, this is so far working out ok for me.