1def pures are just cool to have, it makes the game more of a challenge since a lot of things are harder, but you do get awesome hits for your lvl. And I've got a tank ranger with 70 def myself as a main but pking with it is useless if you dont wear barrows in p2p. I pretty much own in f2p bounty but that's boring as well.
I'm currently working on an 1def pure a bit.