if it sound good then cool edit is the thing to use.
i use sonar for recording and mixing
i use sekd's red roaster (i.e. samplitude master) for mastering.
this is a funny thing... mastering. use to be that people referred to mastering in terms of putting together multiple songs on a release so that the songs are level. now people speak in terms of making an individual song sound as clear and loud as possible.
if i am just concerned with one song, then i'll go ahead and 'master' in sonar and then just use nero or easy cd creator to do the burn.
if i am concerned with multiple songs, then i'll mix them individually in sonar, export the audio to 24bit/48khz wav files, and bring them into Red Roaster. Red Roaster allows me to do frequency analysis on the individual tracks, and set EQ, multiband compression, and limiting on the individual tracks in addition to fades, crossfades, and volume settings.