All my bikes growing up were the cheap Schwinn's of the "looks like a lightweight road bike" class. They all had the Ashtabula cranks on them that were probably 165mm or less in length. The '79 Varsity that I rode for 36 years was one of those cheap bikes. So small crank arms is what I was use too. I replaced the cranks on all my subsequent bikes with 165mm cranks. Mainly because I felt like I was thrashing too much with the longer cranks that came on my subsequent bikes after I stopped riding the Varsity circa 2015.

You may or may not like them. That's about all I can say for certain. And you already said that yourself. I do think you'll find you can spin a smaller gear ratio faster which might help on hills. But whether that will be a benefit is something that only you can decide.