The ftp server is more populated and there are more mounts. PVP alot there, about fractions i cant say a thing. But ftp has a huge disadvantage
...the cash shop... u can choose wether to buy or not ..but its neccesary to spend a lot of money when u want to have fun in pvp there. U can buy some items to be stronger. There are items called runes they make u strong but they are expensive, prices i dk but many many euros.
You have to farm over 2 years a lot to get all from Cash shop and many ppl have high runes, top guilds u can enter with high runes too.
But u can Play free there.
On P2P on the other Hand Little Population but PVp too all activites u can do on ftp too on both fractions. No cash shop and no runes
...for gods sake

, only skill and gear, u can be full epic + leveling in 3 months
But ptp has no pvp Mounts and bags are not as big as the ones u can buy on ftp. I have 126 Slots and thats fine for me.
BUT if you spend 21 € for ptp u can Play 3 months thx to a bug if u have luck even 6 months.
There are many Topics like this all over the Forum
Greetings
Taleron