Its the one thats always recommended on here, I've never personally used it.
However saying that, just taking a quick glance the Samsung is higher quality and will give you sharper colour (jesus christ it tells me colour should be spelt color, please stop killing the English language) contrast as its 3000:1 rather then the Acers 700:1 which is very poor and the Acer has over double the response time, which in monitors, is bad ^^
Overall I would say yes it is worth the extra 90, but I would also pick the Samsung Pebble over both as I like the look better =P.
Either way, both Samsung's beat that Acer hands down, feet tied.
Oh and I'm not sure if that Q6600 is the G0 version, and newegg doesn't return any hits on "G0" so I'll leave that to someone more versed in US websites, as other then Newegg, I have no idea where US people get their parts from