Turbo/Rammer, Aiming Device and Stabs are my go to for pretty much any tank. Always have been and probably always will be, unless huge changes of course. Sure, hardening can keep you alive in some situations, but this setup will improve accuracy and mobility in any situation. Always.
There is no point using improved aiming without using vents, vents make everything a bit better(including accuracy). With vents without IAU accuracy is only 0.1 worse, but everything else is a bit better. I only use IAU with vents.