Here's an important question. Are they willing to do all the work needed for editing a feature? It's a TON! In a feature the characters evolve and change so small details in one part effect major plot points later. There's a long string of continuity to keep in mind. I've had editors quit on me before. I ended up editing myself and actually I love editing now so maybe it was for the best. However, I've come across a few that really weren't committed to the long LONG hours required. Best of luck.
Well, if none of them have experience editing features... which one has done the best work on shorts?
I can't tell. They look similar. Actually I like the least experienced one's cut but unfortunately his style is not what I want for this feature.
If he is a good editor probably he can adjust to the editing style you need!
Taking into consideration everything you've said here the
choice should be easy. Choose the person who you feel will
be the most dedicated and most reliable. One should already
be eliminated so you only have two to choose from. If they
are both equal in dedication, experience (or lack of) and both
friends, then flip a coin. I'm serious. There is no way to know
who will do the better job until you are working with them.
Hell, you don't know for sure YOU will do a great job but you
know you will try your best. So will whoever you choose.