Fish, I love this thread!
Have you pruned these trees or just let them grow? I know I have a few crabs planted and I have pruned them this year. I have several planted only about a year or two old.
What type of spacing do you give them?
Thanks Buckhunter!
Kind of a convoluted answer, but here we go. Yes, i do prune them. But not as detailed as my orchard (fresh eating types) trees. Crabapples will make you bleed!

. I focus on cutting out branches that shade others. Not much snipping work.
As for spacing, i planted the trees originally on 8 foot centers. It was cool seeing all the different growth patterns of the trees. Some were dwarfs with purple leaves. Others were vigorous and green leafed. But 90% of them either had diseases, or pea sized fruit.
I gassed up the chainsaw one winter a few years ago and dropped every other tree. This put my spacing at 16 ft. And gave me some great smoking wood.

Many of the remaining trees were grafted over to dessert apples, like Liberty and Gala. Others were grafted to one of my favorite crabs, like Lemondrop and Puckernugget and September Sun and.... aw heck, you get the point.
I cut scionwod from Lemondrop today. I stood back and admired that tree. Its a biggun.