I believe in multiple disposable seam rippers so I buy them often and on sale or with a coupon, I usually get blue (Dritz?) larger handle ones. I have a slightly more expensive padded handled one, I think by Singer (its pink and white, didn't see one quite like it on my search).
The little ones cramp up my hands. I like that pink and white one, not so much since the dog got it and chewed the end a bit but it fit my hand well.