i am a long time user of powertracks. also have used ntrack. there is a new version 9 out that blows all the competition away imho. particularly on the midi side which ntrack does not have. one exciting feature is vocal pitch correction and harmonisation.
heres the link. try the demo. take the video tour.
pgmusic.com click the powertracks button at the top of the page.
note. powertracks has a slew of built in effects like noise gating, echo, rvb,
AND SPECIFIC FX SETTINGS FOR BASS PLAYERS, guitar players, vocallists and drummers that ntrack does not have.
also - frankly i prefer the ease of editing audio tracks in powertracks.
whatever software you decide on make sure you have 512 ram and a 1ghz plus processor and fast hard drives.peace.