Hi there!
Using a 500 series Hassy I shot portraits with a 150 and an NC2 for decades. Can't beat it even today.
Do check the 180's minimum focus distance, AFAIR it's a little long to get a decent headshot. I do remember the studio I worked in having both and also the 250mm, and settling down on the 150 after trying all three. Perhaps it's because I like to talk with the model as I'm shooting and didn't want to be too far away.
Landscapes... hmm. didn't use either lens for landscapes, so can't advise on that.