I don't really see a lot of use for a pre-hacked mouse in this day and age, unless it's VERY inexpensive (as in, like $5). Back when the $40 Opti-Pac was the only professionally-made optic encoder, a pre-hacked mouse was a pretty tasty looking option. However, now there's the Opti-wiz from GGG for only $15, so there's not much reason to use a mouse hack unless you're doing it yourself for free.