I'm not sure, but I don't think a Samsung has ever been used in the BenQ FP241W. Has there been a service menu screenshot or any other evidence? (prad.de does make assumptions). The AUO panel will be better than the Samsung in the Dell 2407 by a noticeable amount. If you happen to get a Samsung panel (which like I just said is doubtful), it may have the same (perhaps without banding issues) image quality.
http://www.bit-tech.net/hardware/2006/11/07/Benq_FP241W/4.html
It wouldn't even be a question for me if one monitor had noticeably better image quality, but I put image quality above 'extras' (more USB, card reader) in a monitor. I can see how the lack of 1:1 would be an issue (for ATI users). You can use PowerStrip to get around that, if you ever happen to need it. Future graphics cards or driver/firmware updates may eliminate that problem.
http://www.bit-tech.net/hardware/2006/11/07/Benq_FP241W/4.html
Both the colour ramp tests for greyscale and for colour delivered smooth grading and no colour imperfections, even at the furthest ends of the scale. In this respect, the Dell was definitely outclassed and this monitor established as a cut above the rest - it was at least on a par with the Samsung 215TW, if not better.
It wouldn't even be a question for me if one monitor had noticeably better image quality, but I put image quality above 'extras' (more USB, card reader) in a monitor. I can see how the lack of 1:1 would be an issue (for ATI users). You can use PowerStrip to get around that, if you ever happen to need it. Future graphics cards or driver/firmware updates may eliminate that problem.