I posted a review in the "Prodigy reviews" thread, that I thought getting a Prodigy would be the same experience as my 401 PT (without the in-line battery) using a Kensington PP, only wireless. Not quite.. IMHO, no comparison. Maybe it is the manual switch maybe it is the 801/901 atty. But I do have to say that the Prodigy blows it away. Of course this is only my opinion..take it for what its worth.