It's not comparable, the n°1 problem with that, other than the obvious boost in speed, is that even when you're using the handbrake it moves you backward. Just restore it to the old values.
I think the reason you notice such massive speed increase from the recoil compared to other cannons is because the damage is set so high on them. I'm sure you could go that fast back whenever security first changed arty. Try setting a cannon to 2000 or something and you would jump to max speed at the first shot, it's hilarious. I didn't know about the handbrake thing though, that must be new.
It's not the damage, it hasn't changed between 2.14 and 2.15 and this huge recoil is not happening in 2.15.
I'm going to start off by saying holy shit was putting scripts into vpks a bad idea. Having to repack them every time to make changes is a giant pain in the ass. I can understand art and stuff that doesn't require constant change but not the scripts D:. So yeah, damage does affect recoil of cannon shells, it's just arty wasn't affected at all in previous versions. I tested real quick by just changing an arty cannon to regular tank cannon in 2.15 and had the same speed increase. Just to make sure I also changed std cannon or something to do 1000 damage and from a dead stop jumped instantly to 100 kph. Actually when I think about the various damage values it seems like when recoil affects a tanks speed it's about 10% of it's damage, though I think force or something else also affects cannon recoil but it's too long since I played with it and I have no interest in testing scripts when it's a pain to change. In any case the only change in 2.15 for arty was making arty predicted right? I assume some code was copy pasted from tank shells to make that happen and that's what's causing this because cannon shell's recoil has been able to increase a tank's speed for quite some time.
You can find the up to date scripts including changelogs here: https://git.empiresmod.com/empires_public/empires_scripts Yes, we made artillery predicted.
That's what I said... Can you imagine how much longer it's going to take me to set up my server for 2.15 just because of this one change?