I flew one up until mid June.
As for the thingmebob for storage i have no ideas how much it cost. If my pax wanted to take a bag then it went on their laps. I tell them it is a saftey feature that, you know extra padding in the event of an incident or landing on water (not that you land on water without ski's)
The undercarraige can be costly to maintain just like any other retractable. It is just a pain in the **** to work on. One good thing is it is the good ole Cessna type sprin undercarraige and not oleo type (apart from nose wheel).
When it comes to taxying, if i am on grass or rough ground i always taxi on the rear engine. That way i am limiting the chance of anything happening to the front prop should i end up in a dip that is a dip to far! plus you dont chuck a load of crap all over the AC.