I remember a big thread about this few years ago.
Is one BETTER than the other, or are they just for different things? I did a lot of my own research a while back, and built a pretty good circlet druid which I thought was better than pelts but I forget why and don't really want to think it all through again.
His setup is:
165 fcr
99 fhr
7.8k Life (lvl 36 Oak)
5.8k Tornado (lvl 45)
2/20/20 Circlet - 73 Life (Ruby/Shael)
2/20 Amulet - 48 life
10fcr/24fhr belt - 56 Life
2x fcr rings - 5/19 Life

Hoto
All 40+ Ele GCs / 20l Scs
With pelt, you lose 2 oak and gain 1 tornado