In my experience, each of these three cameras is capable of churning out some impressive shots, though they all have slightly different personalities. The 12-megapixel main camera is arguably the most well-rounded of the three: Its photos are packed with detail and bright, if occasionally quite warm, colors. The wide-angle camera also fares well, and the photos it churns out provide ample detail and an appropriate sense of grandeur when shooting landscapes. The colors it produces are a touch more neutral and even downright cool at some points (though the phone's HDR might be making the difference a little more pronounced). The telephoto camera, meanwhile, is the one I'd rely on least. Some of the photos it churned out were a little fuzzy and indistinct compared to the wide and standard sensors.
Expecting people to switch between three cameras manually can seem like a little much, but features like Triple Preview help. It offers a thumbnail-size preview of what a photo taken with each of the three cameras looks like, and it's so handy I wish it were on all the time. I can't say the same about the phone's Triple Shot mode though. It allows you to shoot a photo with all three cameras in quick succession with a single touch, but the results tend to be pretty disappointing.
Here's the big issue: When you're framing up your shot, the camera locks focus on whatever's in the center of the frame and keeps that focus for each shot. That means the wide-angle shot and standard shots generally come out looking good, but zoomed photo is almost always soft by comparison. Hopefully LG fixes this over time, because right now it is so clumsy that it barely seems worth using. The phone also stitches these three photos into a short video with zoom transitions and music, but since that telephoto shot rarely looks good, I can't imagine using this often.