Sounds like the ZR24w could have done with some calibrating. And it seems that BenQ has a hell of a lot of inter-panel variation. I hope you're pleased with the G2420HDBL - as you say it's £150 which makes it a budget monitor. If you get a good unit I'm sure you'll be happy with it. I will receive an XL2410T on Friday so I hope for the sake of my review I get a good unit, too.
Thanks!, but my bad luck continues. I received my G2420HDBL and it has the same vertical stripes and a dead a pixel on the middle right hand side. What's with these 24" TN panels. Think I'll just go back to 19" LCD's until the situation improves. They are not fit for gaming because of the awful banding. This one even has a round dirt mark on the right hand side, that can clearly be seen when there is motion. I now have to pay another £16 to send it back. At this rate I'm going to be broke before I get a decent monitor.