By this point we've had quite a few TLPs many with different exp rates. At the Phinny/Coirnav exp rate it made more sense to factory farm quest items in Paineel than actually play the game. At the "standard" exp rate (Oakwynd, Teek, Mangler, Aradune, Agnarr) it's tolerable in a decent group but quite severe otherwise. The time/difficulty/enjoyment calc is going to lead a lot of people to conclude that buying a PL for at least some of the trip to 60 is a better use of resources than grinding. You want people playing your game instead of paying to not play it or otherwise engaging in behaviors that circumvent a primary gameplay loop. Showing up to a TLP after people have leveled is a chore, switching mains or leveling alts is incredibly time consuming and even twinks aren't enjoyable as they should be given the raw numbers on how many things you need to kill each and every level. Ideally you want the leveling experience to not be something people are paying to avoid and for the people that still do to minimally affect the rest of the game and economy.