I fitted 70 Interdictors yesterday (Fitting + Rigs + Cargo).
Normally this should take under 1min per ship in average.
With this new glorious UI, it took me over 3 hours.
Loading isn't the issue at all, its terrible UI design and finding what the fuck your looking for.
You take a shit UI, add 20 updates to it. And you end up with a less shitty UI.