Population's in MMO's changing in a guild is nothing new. Most LoD will agree that UO was the best Full loot PVP game around 10 years ago. Our membership varied from 8-85 like a roller coaster the whole time we played it officially.
I can play darkfall and find PVP in the day time PST with in 15 minutes of logging in, I cannot consider a game like that dead. It might not ever have major numbers but as long as people are enjoying it who really cares?
I would recommend the game, it is the best Full loot, Fantasy PVP game out. It's only competition is Mortal Online and that is still a mess.......