To answer your question, I personally don't think it's worth it, but it does slightly yield better overclocking potential.
But... may I make a suggestion? If you can deal with mail-in rebates, here's a 2GB pair of Crucial Ballistix
(PC2-8000, 5-5-5-12, 2.2V) at Buy.com for $120 after a $40 MIR. If you haven't bought from them before, you can use this $5 off coupon
to save an extra $5, plus you can use Google Checkout (if for the first time) to save an additional $10. At the end of it all, you have 2GB of DDR2-1000 memory for $105.
And even if you can't use the above two, $120 is still pretty dang good for that memory. Just a suggestion.