I picked up a nail on my brand new ME880, had maybe 500 miles on it. Must have grabbed it just before stopping at a restaurant with Nick (ohnopopo) in Plattsburgh. Came out, and apparently when a Metz goes flat it doesn't sag very much. Not like a car tire where the rim sits on the ground. Enough that I didn't notice it.
Took off and instantly noticed a low speed wandering feeling. Minor, but detectable. Having never had a flat on a bike before, I didn't really know what it felt like, so I blamed it on the grooved road I was on. Picked up speed and it got better. Until I tried to tank an on-ramp at maybe 50mph and had a major pucker moment when the bike almost had a tank slapper....I came within maybe a yard of nailing the guardrail. Of course now I had no choice but to continue and get on the highway, to get off again and look things over. Couldn't take it much over about 70mph, and it had a constant wiggle that got worse if you tried to speed up.
Got to the first gas station I could, the rear was flat. Aired it up, and it held just long enough to get home. Found a nail smack center of the tread. Pulled it, used one of the generic tire plugger kits. The first one didn't last long, after a couple hundred miles it started to slowly leak again. Did it again, this time spinning the needle tool several times at the suggestion of a friend(despite it saying NOT to do that on the instruction). It's been fine since, not losing any air and I've had the bike to 140+ with the plug.