Having never really played the soldier class all that much, I was wondering what would constitute as an impressive armor rating.
I’d say 2500 is a great armor value with more of that being obviously better. I do think 2200-2300 is fine if backed by solid physical resist (at least 25% physical resist).
I never played Soldier either, but from playing my 5 characters that armor value from 1600 to 3000 I can say that anything above ~2200-2300 armor feels pretty comfortable, as long as you have ~15-20 phys res and sustain. I am talking campaign. 1600-1900 armor even with phys res as high as 25-30% feels squishy.
Overall, I became kinda disappointed with physical resist, it doesn’t feel like it does a lot really.
For tank builds 3500+
For generic builds 2500+
If you aren’t doing a lot of physical damage yourself I think physical resist becomes a little less important. It took me a long time to realize why my blademaster would pop himself vs reflect with a high HP pool and capped res.
So for a build I’m testing, I managed to stack around ~3.2k armor. But my phys res is shite (a measly 3%).
How would this pan out?
Well. My 2h purifier had that pre new crucible but also has seal. Now for 170 I got an extra 8% phys via a formidable affix and compass devotion. In 0.6 Ulo will also give 8% pys res. Depending on your build, you should do fine. just don’t try catching Aleks meteors with your teeth:)
PS: The build I’m guessing you are referring to shouldn’t really get direct hits like that 
Weeeeell…it shouldn’t in theory