Whether it's graphically superior to 360 is very arguable. In fact most multi-platform titles to date have run better on 360 leading to the opposite conclusion.
If you want to say it's the most high tech system because of built in hard drive, it's quieter and more reliable, Blu Ray, or built in wireless feel free. But just to say it's technically superior because it's more expensive is foolish. In fact, the PS3 is nothing but a $399 console with an extra $200 to pay for Blu_Ray. A $399 console is the same as 360, so even your own flawed argument is proven false.
"If you compared Playstation 3's first games, with Xbox 360's, you will see that Playstation 3's game are slightly nicer in visuals."
This isn't valid because 360's alpha and beta dev kits which launch software was mostly developed on were severaly underpowered compared to the final hardware. PS3 dev kits had no such restrictions, so PS3 titles looked better from the start, however 360's graphics have improved more because of it.
Just look at 360's early lineup. The system didn't really get a graphical next gen game until GRAW in March 06. Now it even has dozens of games that blow away GRAW. PS3 games will likely improve (Drake, Heavenly, Ratchet) but not to the degree of 360. PS3 games came out of the gate using most of the system's power (Motorstorm).
