Does this spells the end of leechers?

In my opinion, the best way to stop leeching without ruining party exp is:
You have to be within 20-30 lvls of the character to leech. This would not stop the high level characters from leeching but it will stop lvl 78s from leeching lvl 140s. And the party exp would be increased to encourage partys.

I think it's fine if a low level character leeches a higher level one. It's natural to want to help friends level faster. It's just when a low level character trains twice as fast as normally possible in a party by hanging afk on a rope while the high level character kills things that something is a little broken. The new system seems to correct this, as lower levelled characters leech less exp from the party than high levelled characters, and the total leeched exp is much less than the exp gained from killing.