On a steep hill, yes you can walk behind it....but most of the times I will ride down something a little bit steep. If it's too steep....I have my walk behind aerator (RIP: Lawn Solutions dual hydro).
The LS dual hydro might be a collector's item....I'm not sure if they ever got 5dual hydro walk behinds made? But I got one by calling once a week to check how they we're coming along.
Aeration accounts can very....and since it's been so dry here... I am waiting for some rain before I place my ad in the paper.
For me to justify the cost.... it makes the job so much easier and quicker... I can do other work that I would normal be stuck aerating the old way.
As long as you don't live in Northern Illinois....it's a great machine. If you live up here....it's too much money and you don't want one....lol. Since I have one.