I think Hot and Top are sorted according to upvotes + boosts (weighted x2) less downvotes. I think the plan is reputation will work the same way (once it gets fixed).
...but reading this thread I wonder if that needs a rethink - people seem to boost rather more liberally than expected/intend in order to game this algorithm.
It was thought/expected that, since boosts effectively retweet the comment, they would be used quite sparingly - this is why they have a relatively high significance.
We could probably do with some clarity on all of this because this line of discussion has been repeated many times and there is quite a lot of hearsay and misinformation being parroted. @Ernest ?
Teppic