I think there has been many over the years, I can tell you from my experience and just my opinion. I had an LE years ago and ended up selling it, picked up a pro from a friend and awesome seller this year and IMHO I love the way to pro shoots over the LE. There were just some things about the LE that were little hiccups for me.
Bicycle girl ramp aside from needing foam under the flap to prevent damage to the PF, it just never seemed to sit right at the split joint and I was getting a ton of rejected shots no matter how many adjustments I tried.
The second magnet in front of the well walker was cool to have but not necessary, along with the crossbow feature.
Woodbury drop target, that dam decal would always seem to keep peeling off and jam the drop target often so I don't miss that as well, actually really like the flow without it.
Okay the lockbar Walker Bomb button, this to me is the biggest value loss when going from a LE/Prem to a pro, but to be honest again not a 4000 worth of a loss. However it's all about what you prefer.
For (me) I love the pro and very satisfied with it as such that for my liking I don't feel the need to upgrade for the few differences.