My biggest concern is that if you can level 1 - 30 in two days... and 30-50 in another week... that means a lot of mid level areas/content is completely obsolete.

Also, what about all the R1-45 gear that is completely a waste. Why would you really buy armor or weapons that will be obsolete in one day. Why would you ever try to convert materia of a R35 item since you will never use it?

I think the power leveling shifts EVERYTHING to END GAME content. Everything that comes before that won't be used (content, crafting mats, crafting gear pre rank 50).