Advice about ext3, please

[Paul E Condon <pecondon@mesanetworks.net>]

I'd like some confirmation, or refutation, of some reasoning:

I have a USB external hard drive. It came with vfat fs, but I want to
write an ext2/3 fs on it. All my internal HD are ext3, but should this
one be ext3, also? Doesn't ext3 essentially write everything twice,
first to the journal, and then to the actual target location? This is
OK with an internal bus interface from the CPU to the HD, but USB is
not so fast. So I think I should not use ext3 for this HD. Is this
correct?

TIA
-- 
Paul E Condon           
pecondon@mesanetworks.net