It is jittery and totally unstable. I sometimes run Limewire, Cabos and Acquisiton simultaneously to see which program gets the really hard-to-find tunes, and it is not even close: Acquisition pulls those rare gems out of nowhere, while Cabos and Limewire go chug chug chuggin along. But I have to keep force-quitting and restarting it over and over, because it goes down ALL THE TIME and frequently! I still prefer it over all the others out there; there is no contest here: if you are looking to download a particular song, this is the product to use- even as unstable as it is.
When they correct that problem, Acquisition gets 5 stars- until then: 4.
By the way, I have a Mac G5 Panther 10.3.8