The PA46 is prone to icing and has quite a few quirks such as not having an automatic door for the alternate air source. When this ices up the performance drops off and unless you are on the ball monitoring it can go unnoticed. It is also prone to icing up of the static vents and again know where the alternate static source is located and when to activate it requires a through knowledge of the aircraft. I never flew it low level more than short hops between positioning airfields. I generally always flew it high 20-25,000ft as a rule IFR regardless of conditions and always trying to end up on an Instrument approach where possible. As a VFR aircraft low it has very poor visibility low out the front and requires a lot of work to keep a good look out so was mush easier just to go full IFR.
I have seen the static source freeze on it so that the altimeter and VSI are frozen and of course the reaction could be to shove the nose down further rather than CRM a solution and go to alternate static.