I would take a four cylinder 4000 gasoline S-O-S (or even a five speed) vis a vis a 3000 gasoline unit (possibly excepting a S-O-S model) any day, regardless of other options. Multiple reasons.

Diesel models: Subject of another thread.

Dean

Mis-read the OPs original post. Thought OP was comparing a 4 cylinder 4000 to a three cylinder 3000, in which case see my previous comments.

The three cylinder 4000 is considerably heavier than the 4 cylinder 4000, has improved hydraulics, and double reduction axle. That said, PTO HP of the earlier units is about the same as that of the 4 cylinder 4000 (diesels excluded (see previous post))and the 4 cylinder is considerably more nimble.

I've owned and used both and prefer the 4 cylinder for my purposes.

PS is a red herring. Aside from this forum, I've never encountered a "distinction" between "power steering" and "power assist" steering. All power steering is power assist steering, though there are multiple ways of implementing such. Hydrostatic PS is a different animal, however, though unrelated to this discussion.

Dean