Hey Herrsavage, i'm definitely not the one to be answering your question based on first hand experience, so hopefully someone else will chime in. However, i did just buy the black/grey headed "limited" Bonito, and before i did, i think i researched NovaRossi engines to death on the forums! Seems like the general consensus was that the Bonito was too much power to tame in a buggy, and generally more suited to truggy. That, along with the decent price, is why i ended up with a Bonito (to use in my old MBX-4RR buggy). I've got less than a quart through it so far, but already showing signs that it might be a total menace, which is what i was looking for! I do have a feeling, however, that either of these (Bonito or Virtus) is going to more than scratch the "more power" itch for you.

Again, hopefully someone with more firsthand experience will chime in on this "which engine" inquiry!