I have the Hazro 30" monitor and the HP one that uses the same panel as the Dell U3011.
Regarding the Hazro, it performs very well and I'm quite pleased with it.
The HP is a tad bit better but costs £200 more.
Both use no scalars/OSD which means there is no input lag. The Dell one has a scalar and has some input lag compared to the Hazro and HP. It has more connectivity options however.
For gaming, watching movies, browsing and 3D work both are amazingly good.
Minor annoyances: The Hazro screen gets hot when active like a mini radiator. Good for cold winters, not that good for summers.
The HP stand doesn't rotate to each side like the Hazro one.
There are some reviews in the monitor section by Duff man for both screens. Have a look at those.
Hope that helps.
Rara