To OP, it maybe a good idea to include the panel vendor. So far we have:
9C8C (?)
9C9E (Samsung)
9C9F (LG-Phillips)
9CA0 (Chi Mei)
9CA1 (?)
9CBD (LG-Phillips)
For people with 9C8C and 9CA1 panels, can you please run
SwitchResX and check the vendor info?
Most of these panels in the new 13" UMBP are brighter and sharper than the previous model. It all comes down to personal preference. Some panels are a bit yellow, others are a bit blue, which can be corrected by color calibration. If you experience a blue-purple florescent light effect even on an external monitor, then there is something wrong with unit, not the LCD panel.
The light ripple-wave effect appeared on all Nvidia chipset model (it's not LCD panel issue, it can be detected on external monitor also). Apple will need to release update WebKit to correct this issue, as it appeared under Safari, Firefox, but not in Opera browser. Some people also reported ripple-wave effect does not appear in 10.5.5.