>>2693459Ektar isn't worth it if you have a lab that does the E-6 process. Slide film is better in several ways, and I've found it easier to expose than Ektar, as paradoxal as that is. Ektar has a terrible tendency for cold, bland tones and blue cast, makes everything look dead, and is almost impossible to completely fix in post.
Portra is probably the best all-rounder film. I'd say Fuji Superia Premium, but it's Japanese market only. Of the Kodak line, Gold and Ultramax are great when you're on a budget, Portra for when you really need the performance. Ektar only if you can't shoot slide film for some reason.
Fuji, in the time-honored Japanese tradition, reserves its best stuff for the Japanese market only. Fuji Superia Premium is much like Portra 400, but costs less. Most importantly it lacks the heavy color casts of Super Xtra. Fuji Superia Venus 800 is a great high speed film, surprisingly low grain especially in daylight conditions which completely blow up stuff like Natura 1600. Too bad these aren't for gaijins. Superia Xtra is inferior to Kodak Gold, mostly because of the color casts that exaggerate either red or blue. Pro 400H is weird, exposing it like any 400 ISO film just blows it all the way to hell. I don't really like it enough to try and figure it out. Natura 1600 is super mushy in daylight as you might expect, but it's great for late night street work.
No experience on Agfa yet. I have a bunch of their old stuff in the freezer though, just need the occasion.