I was not there when the failure occurred, but my husband says that the only warning was a split-second "squeee" sound right before the "bang" (which he now describes as more of a "clang").
We have not noticed any other performance changes or noises other than a slight decline in mileage over the last year or so. We attribute this primarily to drag: The car is sporting two extra antennas (XM radio and CB), a broken spoiler (now held on by gaffer's tape - it's a hard car to get a grip on to push in the snow - I broke one side off with my head), a missing underbody panel (an icy snowdrift), and a broken passenger side front-wheel spoiler (more gaffer's tape; a curb, I presume). We are now averaging 62-63MPG instead of the upper-60s and above that we frequently achieved in the first couple of years. My husband is a big guy, so we often operate over gross. Our best one-way trip was 92MPG and our LMPG is 59.7.
Oil change intervals have ranged from 3000-5000 miles over the life of the car, which we bought new. It has been run on Mobil-1 0W-20 synthetic since the first oil change, and we have used either Honda or Fram filters, depending on availability. The only exception was one dealer service, done at 120K, when we had the valve lash adjusted.
We live in the country on a dirt road and have a quarter mile of steep, rutted gravel driveway. It has been driven across the pasture on occasion when the driveway flooded and froze. Most of the car's miles are freeway driving to work (often 500-700 miles/week) and it has been on quite a few long road trips. It's on its third set of tires. We ran the first set WAY too long and narrowly missed a blow-out. Just try to buy tires for an Insight on a holiday-weekend Sunday. We got just under 70K out of the second set.
We have not had any other issues with it except an IMA control module failure early on, before the recall was issued. The dealer handled that very graciously, providing us with a rental car and a gas allowance to make up for the difference in mileage. Even without the IMA, the Insight got better mileage than anything else they had! When the part proved hard to acquire, they removed a module from a new car on their lot so that we would not have to wait or come back.