I'm with the ForkTailedDrKiller - I'm happy with my C210 and I don't think that I need a twin.
However if I was going to move up to a nice twin, the C414A Chancellor would be high on my list.
I'd say running costs on the C414A would be cheaper if not the same as the Baron 58P and it's got extra seating - plus its a cabin class twin.
I reckon it's amazing what Cessna have done with that airframe and wing on what is essentially the same power as a C310 or Baron (50hp more if you want to be picky).
Beware of the C414 RAM conversions with winglets here in Oz, as CASA halves the spar life. Apparently there is little or no data on the twisting loads that the winglets put on the wing & spar therefore we halve the spar life to be on the safe side.
If you don't need all those seats then we're back to the C303 Crusader again.