Specs on these are as follows:
Sony G420s Aperture Grill, 0.24 dot pitch, 1600x1200@85Hz
Samsung 900NF Aperture Grill, 0.25 dot pitch, 1600x1200@75Hz
Flatron 915FT+ Slot Mask, 0.24 dot pitch, 1600x1200@85Hz
The + on Flatron refers to the built in USB ports.
While all three are excellent monitors the Sony and Flatron are better than the Samsung due to dot pitch and refresh rate. The choice then comes down to Aperture Grill or Slot Mask. Some people complain about the support wires on the Aperture Grill being visible under white background conditions. I for one find them distracting. Bottom line the Flatron wins.