I thought I’d take a little time to explain the terminology because these two terms are frequently confused.
Simply put, top is combed fibre that is either commercially combed or hand combed so that all of the fibres are aligned and the shorter fibres are removed. Top can then be spun using short draw which maintains the parallel fibre alignment to create a worsted spun yarn.
Roving is carded fibre which can contain both short and long fibres. The fibres are not aligned parallel to each other. Roving can then be used to create a woollen spun yarn when spun with a woollen spinning technique.
My preference tends to be a worsted yarn because it has more strength and drape than the woollen yarns but it is a personal preference.
The benefit I find, to hand combed top is that the top is less compacted which makes drafting easier and prevents your hands from hurting after a long period of spinning. I add this because myself and several spinners I know have said how their hands get sore sometimes when spinning with a compacted or felted top. Hand combed top also produces a much less dense, more airy and elastic yarn.
I hope this helps.