Just last week I replaced the tires on my commuter to Continental Contact Plus (700x32). I made the switch because I lost confidence in the original tires (WTB Slick, also 700x32) after a couple of flats over a year or so (i.e., not that many, really, and may have occurred with any tires). In any event, after the flats I decided to prioritize flat protection a bit over weight. I was torn between the Schwalbe Marathon Plus and the Contact Contact Plus, but ultimately went with the Contact Plus because they were a little cheaper and lighter, yet still seemed to be well-reviewed in terms of flat protection. I don't notice a huge difference in the feel on the bike, but I feel less worried about flats. Whether that really means I'll be less prone to flats is less clear, but I'm enjoying the improved peace of mind.