They both have their merits. Can't really say I prefer one over the other.
Kinda need a better clarification of your meaning of "slut" though. A girl that will suck off every guy in school, but doesn't fuck, is a slut in my opinion. Plus, many girls nowadays have anal sex but are still technically a "virgin" since they haven't lost their cherry.
Being a virgin doesn't necessarily equal being innocent. Nor does not being a virgin automatically make a girl a slut. To me a slut is a girl that will fuck around with anyone who comes along with no emotional connection needed.