reliability is also relative, if you use the brake for 4 months then get a new one it does not matter as much... disc vs. hs33 is another deal, since it´s 2 very different feeling brake systems..
but i agree reliability is a factor aswell.. that is why i have an heavy king hub on my otherwise pretty darn light bike...
I think i´ve read that he is very happy with that front brake... Don´t know if i want to get involved with magura products again though:P and also the wheight savings over a carbon/ti hope trials with the plastic hose is subsantialy ( sure of misspelled) less.