Out of interest, a b or a C model? I used to run a b model and had no problems with the engines going to tbo, but I dont think the 421 is really a UK machine unless you are going flying for at least an hour. Short sectors can play havoc with the engine handling, and the aircraft needs a decent length runway, especially close to max gross. The wing spars are getting a lttle tired on the older ones(they are "lifed" in Australia btw), and ironically, the older "b" models have a better spar life because of the tip tanks.
Still , I flew one round europe and the usa for 3 years and loved (almost) every minute of it. 22,000 ft and 220 kts, try telling Milan you're not a king air!
Best of luck. I'm going to look at the old piccies now...sniff...