The Conquest line when first introduced, were German components, but were assembled in North America, at least for the scopes. I do not recall if this was the same for the binos.
Cannot say where this is today.
While Zeiss had an enviable reputation for a long time, I still believe that their higher end lines are still quality products. Their old 10 power binos were the ones that all others were judged against, and were great pieces of glass. A friend had a set for many years, until he upgraded to a RF binocular. Clear, bright, rugged and lightweight, I almost bought them for my wife, but she did not like how they adjusted for her eyes. I should have bought them for spares anyways...
As for warranty and customer service, I cannot say as I haven't owned any of the products over the years, and never had to use their warranty.
My one and only foray into one of their scopes (Conquest) was unimpressive to say the least. The scope wasn't clear, and the reticle was fuzzy at 100 yards, and I could not get it better through adjustments. And when I took the scope off the rifle and returned it for an exchange, the tube was crimped, even though it had been mounted and torqued to spec by the people where it was purchased and mounted on that 6.5x284 rifle. Not a great first impression and I have stayed clear of the Conquest line ever since.
I have typically gone with other scopes as they were usually lighter and shorter than the similar Zeiss scopes.
I really liked the features of the Duralyt line, but they were heavy scopes when compared to similar Leupolds and Swarovski models, so I never did acquire one.
I can say that those I know with the Diavari and Victory products do like their scopes.
I missed out on an older Diavari 1.5-6x42 scope last year that would have been nice to compare to the similar spec'd S&B and Kahles scopes I have on a couple of medium bore rifles.