Only tried the first 2.
Audacity doesn't have true multitrack capability although I believe you can simultaneously record several inputs, but each track takes a separate window, so it behaves more like an editor (I think wavosaur looks much better, in the case of free editors, plus it supports vst and asio). LMMS has more potential but it is still 'not there yet', for lack of a better description. The interface reminds me too much of Fruity Loops making it look less professional.
Looking at screenshots of traverso, the 'region' window at the right reminds me of protools. I like 'rubberbanding' for the gain envelopes, plus the GUI is skinnable. I'm gonna be watching this closely.