Personally, I dislike the higher rate of fire that you get from upgrading weapons, especially SMGs and LMGs.
This is because I’d like to equip an SMG on some of my soldiers (especially APC drivers and Medics) without carrying an extra ammo bag, but the increased RoF makes the SMGs run out of ammo significantly faster.
This is even worse on LMGs, because on SMGs, if you upgrade your weapons, you get recoil reduction, but on LMGs you don’t.
Unfortunately, if I want to get better dispersion/damage, I must upgrade the RoF.
In my opinion, instead of increased RoF, you could improve the bullet velocity or something (idk)
TLDR: I dislike high RoF because it is not good for ammo management.
I don’t care for it because I want realistic stats. The starting RoF should be slightly under IRL RoF (dirty and worn parts) and the upgrade should “restore” it (via maintenance) to its proper RoF
I want the choice to select the upgrade between better rof or reload speed, getting everything on a single gun is more an handicap on gun with faster/slow reload and slow/faster roof