Where will you be buying from? I'm seeing the 2411Z averaging about $10 cheaper in the US, but for the most part the prices are effectively identical.
They're both roughly the same
unless you're interested in LMB
the Z series is newer and has better blur reduction performance (the ASUS would be stuck with messing with Lightboost tricks for that), particularly when used with this tool:
http://www.blurbusters.com/benq/strobe-utility/
The advantage of the ASUS monitor is that you could potentially upgrade it with G-Sync if you're willing to spend the extra money and risk opening up the monitor for the DIY upgrade.
the minor advantages if you're not interested in either LMB or G-Sync would be that these BenQ monitors have some pretty ridiculous color profiles that mess with black levels (helping you see in dark games for a competitive advantage), while the ASUS has some on screen crosshairs (possibly helping in no-scope situations) although both can be pretty ugly and shouldn't be considered major selling points.