This is a tough choice and I think you definitely should take vigor of the variety into account, since that makes a dramatic difference. For instance, I grafted some Early Mac onto Bud-10 that is taller in its first year than Reine de Reinettes on G969. This isn’t surprising when you see that Early Mac is listed as more vigorous variety based on this list Scott posted a few years back.
It if was me and I was limited to Bud-9 or M111 I would get anything listed as T3 on Bud-9 and anything T1 or T2 on M111 and deal with them via summer pruning. It is actually more enjoyable to me to be actively pruning and shaping the tree I want vs. just hoping the tree grows enough. When you have the vigor you can make choices, but when you don’t you can be stuck just letting the tree grow how it wants to since you don’t dare prune much away. At least that’s how I feel. How much you are going to fertilize and the quality of your soil probably matters a good bit as well.
The danger of Bud-9 is having a runty little tree that doesn’t produce much or grow much new wood each year. All of my Bud-9 on M111 interstems basically runted out because deer browsed them repeatedly. I eventually pulled them out and have pears on OHxf87 and persimmons in their place, both of which are much more vigorous and I am so much happier. So for me, I’d much rather have to do more summer pruning to keep a tree smaller than have a little tree that can’t carry much fruit, especially when the squirrels, racoons, etc. are busy stealing it.
Keeping the animals off the fruit is going to be essential. With this year’s drought, they are desperate and have stolen everything except my astringent persimmons and the apricots and blackberries I got at the very start of the season before the drought was bad.