> sudden line-jumps
This is definitely something needs to get used to. But the biggest advantage of non-smooth scrolling is that it starts and stops instantly with zero overshoot, which is what I hate of smooth scrolling.
To be more clear, I actually use all three types of scrolling, for different scenarios.
I manually drag scroll bar for finer control, and it has no suden jump issue. I also use auto-scroll (middle click) for super quick scrolling (which is kinda like smooth scrolling).