I put autosteer in my oldest and cheapest to run tractor (JD 6400) and now it's the first one out of the yard
At least with your own kit you can know that it is properly serviced up and in the best condition you can get it. With contractors gear you have no idea whether it's going to break down or not.
use a contractor the properly maintains their kit then.
my contractor has reputation for being a bit of a shark - I just don't see it. for silage I can book him a week in advance and usaually he will turn up on the day. his silage acres getting towards a 5000s acre with a ten year old machine - if not older if it breaks down just he gets another forager in from others contractors to keep the acres being picked up. new ones can break down just as much old ones. He does aim pickup 200 acres per day.
15 years ago we used do 500 acres first cut with a trailed and it took at least a week tying up staff during this time which detracted from there usual routine all silage is picked up by contractors now.