I have a BAT HR on a 13.5lb 7 mag LR rifle, and a Stiller Predator on a light weight .270 WSM. Each action seems well proportioned for the rifle built on it. I have not used a Defiance... yet, but they do have a great reputation.
When I was researching the LR rifle, the 'smith I selected opined that he felt the BAT was the best action available, so I went with it.
Bottom line is, I don't think you can go wrong with any of the 3 mentioned.
Can't make a bad choice here. It wouldn't be a hard choice for me though. the BAT would win hands down. I have had all of them at one time or another and when it comes down too it I have never NEVER been disappointed with any BAT I have owned (that's been a couple )
nothing wrong with the others just personal preference. Just like if you put a Krieger, Bartlein, and a Brux in front of me I will take the Krieger lol