Gofatalis I kinda feel like the heavy roof cannons have way faster bullets and therefore a greater chance of hitting something. Despite your large engines beeing the most powerful in my entire mods folder (except for the outdated archons plasma 2x4 thrusters), the pulse beam effortlessly tearing through an entire vanilla shield, half the block behind it and possibly even further. I'm not saying they're all completely overpowered or anything, but they do seem to be way better than the vanilla parts. And the strong bubble shields have an ridiculously low damage-energy conversion, making it way too hard to shoot them down.
Just my impressions tho.
