Also, the nibs look almost identical as well - are they? For the celluloid version, the prices are pretty similar...is one brand considered to be better than the other?
Nakaya's Tortoise Celluloid from www.nakaya.com

Platinum Celluloid from www.richardspens.com

I've also looked at the Briar Wood fountain pens, which seem very cool. Anyone have opinions?
Briar Wood taken from www.Nakaya.org