Yes IUb incorporates more realism like RUb has - reduced gun effect and increased reload time, ships take more damage also. But you can gun them down just takes more.
If you want to increase speed of reload - be sure of crew training/skill and use something like SH3 Commander mod - it has option to increase speed of reload.
Otherwise if more IUb issues we can contact oRGy - he assembled the mod.
g/l