I had a Delta benchtop. Never managed to get a straight edge off it, even
with 2' boards. I sold it and bought a used Delta full size. Perfectly
straight, no problem.

I got lucky. The guy didn't know how to adjust his jointer, and it sure
wasn't working right. Yet I bought it and it turned out to be fine. You
can hope to be as lucky as I was, or you can learn how to adjust a jointer
before you buy it, and don't buy it unless you can get a good straight edge
off of it.