These charts show the percentages calculated as the sum of all positive vote weights multiplied by the most recent total number of vesting shares owned by (and delegated too) the account.
There will be some small inaccuracy because the SP may change over the course of the 14 day period, and only the most recent SP value is used in the calculation.
Also, this doesn't take account of changes in voting power, but to handle all these things would be hard in software that updates on a five minute basis I think. I may reassess this in future, but think it's fairly representative for now.
http://www.steemreports.com/top-voters/ shows only votes for articles, not comments, but I agree it would be nice to show them together nicely.
Yes definitely very representative I would think, but it's good to know the limits of the accuracy. No representation can tell the "full story". But it's already far and away the best tool for this.
If you find the time it would be interesting to see posts and comments separated.
🤓