Audacity is stunning; as far as I'm concerned it's more than good enough to not buy a pro package. Unless you need particularly pro effects, there are no drawbacks; it's incredibly simple to use (apart from the requirement of installing the LAME codec to export mp3) and has plugin support.
Also, after a year of silence they've just recently finally released a new version plus a public beta, so it can only hope to get better
/ 
