I don't think the S90 is Canon's greatest camera. I've had mine for a year and a half and have only had the widely reported issue of the state of battery charge being reported incorrectly, easily fixed by refitting the battery. However the photos are great for what it is.
Other than that I don't think the S9n series is any worse than other cheap compacts. They all try to offer a huge range of facilities for not a lot of cash and aren't really built to last in the way cameras of the last century were. Most will fail after they've been superseded and replaced.
I'd hope something as expensive, and seemingly well built, as Fuji's X100 might last better. There's also less mechanical to go wrong too.