Ultegra 6620 pedal is almost the same as the PD-7810 SPD-pedal. It offers the same stability, comfort, and ease of entry as the PD-7810. They weigh almost the same -- it's just an ounce or two more since its spindle is made of CroMoly steel and the pedals body made from aluminum.
The only important differences are the color -- the Ultegra is not as polished as the PD-7810's. The other difference is the big cost-saver: it uses a sealed cartridge axle unit. This adds weight and sacrifices a bit of the PD-7810's smoothness, but it also brings the price down by almost $100. An excellent value.
(cleats included)