I have several seam rippers...for different jobs.
I use the one with the hook for picking out.
On long seams I prefer the raczor type.
I happend to buy a small (handle looks thick as a pencil) exacto knife for less than three dollars. I was trying to use it to cut sharp corners of fused fabric.
Well....its a dandy seam ripper too.
WARNING: SHARPER than a seam ripper....faster too : )