Hi, the main difference between the old and new system is the period for which the scores are calculated (7-day period in the new system whereas it was calculated on all history in the previous system).
The other changes (allocating VP and such) is more about rebalancing (and the main impact of these changes is to give bigger upvotes to delegators). For the calculations themselves nothing has changed (the formulas) it's just that the sum is made on the last 7 days instead of since signing up on Share2Steem.
After that it's just "eye changes" : estimating an upvote strength, keeping a global leaderboard, but also showing leaderboard for each scoring item...