The main advantage of 24bit audio is during recording. You can afford to have a 10db+ headroom and still have considerably more resolution than a 16bit recording pushing dangerously close to the 0db point. So for live, or for capturing a very dynamic performance without compromising the quieter passages, 24bit is far preferable. Once again, at the mix stage (rendering to final mix) you can afford a fair bit of headroom, leaving your mastering processors a ton of detail to work with without coming dangerously close to 0db (the point of no return!)
I don't know if you have tried, but I seriously recommend mixing a project to 16/44 and then 24/44. Unless the track is crushed, the difference is night and day, for me, at least. The detail in the quieter passages is, if your D/A and speaker chain is decent, quite noticeable.
A nice easy test is to export both files, then import them to two tracks and simply solo them alternately as they both play. No amplitude or phase differences to confuse your ear, simple seamless switching between bit depths. You might be surprised!
I agree that 192kHz is a bit punishing to your rig unless you have top flight gear and a TOTL computer, but 24/44/48 isn't that big a deal, and 24/96 is good enough for almost any pro situation if you can handle it. Me, unless it is super critical, I go 24/44. That way, I don't need a sample rate conversion for CD, which has its own dangers.