Keywords that keep popping-up are 'non-standard' and 'non-intuitive'. The interesting question is: "when are controls non-intuitive?"
Is heavy additional support of the rightmousebutton non-standard?
Windows controls are usuall all leftmousebutton-oriented, (buttons, scrollbars etc.), I'm an avid LMB&RMB supporter, it simply completents the control, offers more features, meaning that you actually save additional controls.
Is a window surrounded with dragbars nonstandard? (like a normal window, but now you can also pick it up at the sides, or at the bottom, to move it around)
Is heavy additional support of the rightmousebutton non-standard?
Windows controls are usuall all leftmousebutton-oriented, (buttons, scrollbars etc.), I'm an avid LMB&RMB supporter, it simply completents the control, offers more features, meaning that you actually save additional controls.
Is a window surrounded with dragbars nonstandard? (like a normal window, but now you can also pick it up at the sides, or at the bottom, to move it around)