Fly to Innsbruck every year, yes there are more than often delays/diversions.
From around my 10 flights in, only 1 diversion so far, that was with Easyjet, diverted to Munich. They had coaches ready and waiting, all signed and clearly told where to meet the coach and sort out our luggage. Couldn't have been easier, to be honest, I don't know that is always the case though. Coach took around 2 hours to get to Innsbruck.
In terms of the Airport, it is by far the best I have ever been to in terms of time taken to get out through passport control and collect your bags, usually around 5-10 mins after getting off the aircraft. Just make sure you get a coffee upstairs and go out to the viewing area before you catch a flight home, really one of the best airport views around!