Well, the best solution is using 10/17 magazines, but good luck finding those!
Yes, I removed the same amount from each leg of the follower - Just use sandpaper on a flat surface, and lightly press the follower down on top. Try to apply even pressure, but still move the follower over the sandpaper in figure-eight motion to try to minimize error. Stop and check often: You can't put material back on once it's been sanded off.
I prefer to remove the minimum amount necessary to give full capacity - In theory, the longer magazine follower legs help the follower to stay aligned in the mag tube. In practice, maybe it doesn't matter, but you'll see longer follower legs on magazine followers of many different double-stack types.
I never shortened any springs, it wasn't necessary. I generally try to make minimal modifications necessary to get things working the way they are supposed to.
The Maglula Uplula is a good investment if your thumbs aren't up to the task. Or, even if your thumbs are up to the task and you'd just like less arthritis in the future. It also makes it much easier for kids (etc.) to help load magazines, too.
