you can also go behind the Kenwood water tower....its steep but doable..
You have me curious about the one you took....
....if you shoulder your bike.
The one I took is steep as well, but it does switch back a couple times. In the particular alley cat we were coming from the west and needed to get to Franklin and Aldrich. I took the regular path (by 394) up to Kenwood Parkway, and that may have been just as good. Either way you have to go up and down one way or another. But you never know when those little shortcuts will come in handy.
I suppose it would be a good exercise to take the bike out there one day and try each route a couple times. It would be a good workout.