Just came across this topic, so sorry for late reaction.
I fly regular on a Cessna 210 Turbine.
This one got it’s conversion in 1994, an Allison 250-B17F is on the front. It got an extra upgrade and provides 500bhp.
We fly throughout Europe with it. FL230 as advertised is nearly unreachable, so we often cruise at FL170-FL210. KTAS is most of the time 190-195.
The BEW is indeed an issue. More than 2 people onboard means leaving some fuel behind…