I'm your height (i generally round up

) and have definately been in your shoes.
When I was 215, I thought 180 was barely attainable but would be perfect.
When I got to 180, I thought that 170 would be super perfect!
When I got to 170, I thought that toning up would look even better at 160.
So ya, it constantly changes. What I found is that between 170 and 186 (what I am again), there's not much change in clothing sizes personally. It's just how you look in the same stuff that changes a bit but mostly only in our own heads.
I bet you look great and that you'll feel wonderful at your next target. And when you get there, you'll make a new target and have the perk of feeling great about yourself at the same time.
p.s. in regards to setting 150 as a goal, that's constantly a question I ask myself too. It seems like it's a whole different world to even consider being below 160 lbs so I can't envision it as a goal. I find it safer for me to just aim for 170, secretly aim for 160, and not even bother with what I should aim for from there.