So one should not wheel until one obtains HA?
No, you should wheel with or without it.
However, if you start really getting into the rocks (especially with bigger tires like 35s) you're going to be in store for a serious arm work out.
I still took mine wheeling without hydro-assist and 35s, but every time I did I knew that hydro-assist was the next mod I was doing. When I say it's almost impossible to turn the wheel, I mean it.
35s aired down to 5 psi in the rocks...it's a PITA!