Hi DC. Before you look to see which is our choice of twin you really need to look at your requirements as far as;-
1. the number of passengers
2. typical sector distances
3. the area in which you operate
4. are your passengers all able to climb into and get out of the skidded versions
5. where your maintenance base is situated and who the engineers are
6. the availability of refuelling stops
7. would your passengers be happy to make refuelling stops
8. are there noise sensitive neighbour/places at your landing sites
the list is not exhaustive so once you know some or all the answers THEN you will probably come up with the answer.
The 109 with the increased MAUM is certainly very attractive sleek and easy for passengers to get in/out. The S version should do well.
The 135 is good but has short range and is quieter than the 109
The 355 is very nice for 3/4 passengers and has a good range
The 900 has a superb passenger cabin but very short range but beefy engines and a confortable ride and is quiet.
So what will meet your requirements?