If you are seriously thinking of buying an aircraft there are Pros and cons for both these types but a low airframe and engine time C-441 would probably be a better choice for a long list of reasons including some already mentioned here.
There is a big Mu-2 thread that was getting a lot of attention a few mo ago.
It would depend on if you wanted to operate PVT or do CHTR as to how hard some hoops might be to jump through on the MU-2, regarding insurance and pilot exp/ training rqmts, especially on CHTR.
Another type to possibly consider along the same lines as a C-441:
If I had the means to buy my own twin t/prop ( PVT or maybe CHTR use) I might seriously consider a low time PA-42 Cheyenne 400.
Refurbished as necessary inside and out.
5 bladed prop option.
There is 1 on Aust register, VH-BUR.
Welcome to BurlAir; Fast, Quiet, Comfortable
A pilots report here-
A few avail on different websites on the net.
IF, parts, operating costs, insurance, maint, training etc were very similar to a C441 that would be a possible viable option.
350KTAS and jet like climb performance.
The TPE331 DASH 14 engines are massively flat rated,( even more so than the Dash 10s) to 1000SHP and can maintain that power to 20-22,000 ft in ISA!!! Thermodynamic rating is close to 1700SHP.
A few pilots I spoke to had good things to say about them.
Not many have seen them let alone flown them as they only made 43 of this subtype Cheyenne. Most now in USA and Europe.
I would love to find out for myself.