Schwalbe Marathon Plus

I recently added two new tires to my inventory. I was sick of getting flats (about one a week), so decided to upgrade to Schwalbe Marathon Plus tires. First off, they are supposed to be "unplattbar" (that's German for flat-less). Second, they have a lot better tread on them than my stock slicks. With Utah winters being what they are, I was in the market for beefy tread, so these filled both my requests.
To start things off, these were the most difficult tires to install. Literally. I have never, ever, ever had such a hard time getting tires on. In fact, I almost gave up. Finally, after several embarrassing attempts, I found the key. I inflated the tube about 4 pumps-worth, stuck a tire-lever under one side of the bead, then got the forearm workout of a lifetime trying to roll the daggone thing onto the rim. Of course I was so absorbed with getting the tire on, that I wasn't careful of tube placement, and ended up getting a pinch flat. This lead to some mental cursing and several under-my-breath comments. I took the tire off and started again after I patched the tube.
On my ride in to work today, I did notice quite a bit more rolling resistance than I was used to. It was not dramatic, but it was definitely noticeable. I'm asusming that the extra layer of puncture-resistant rubber was the cause.
However, when I got to work, I made a discovery that made the pain of installation and the extra rolling resistance worth the hassle: a construction staple. You know those heavy-duty, 1 1/2" staples that they use to attach electrical wire to plywood? Yeah, one of those was stuck in my tire. Miraculously (or maybe not so miraculously, since that is how the tires are designed), the tube was still at full pressure, and hadn't even been punctured. The extra weight on the pedal-strokes is worth not getting a flat.