Personally I am really enjoying PES6, it's like PES5 with all the annoying parts fixed. Much fewer fouls, the ball doesnt go out constantly on the wing, through ball works again, passing is realistic (if you arent facing the right way your pass will suck), the players move more, the diflections are far more realisticly random than in PES5, and there are far more ariel events to keep the long ball useful.
All the people who were expecting a completely different build are insane. If they had to go back to square one after each game they'd never be able to release one annually! You cant program a completely new gameplay engine for a game as intricate as football in less than a year. Most games are in development for a number of years, and if they are any good their engines are used for sequals and/or different games intirely. Whilst they were making PES6 PES7 was probably already in creation. Fifa often feels like they go 5 years at a time without changing the platform, whereas PES 5 was so different to PES 4 that you have to expect a kind of revised version.
And concerning the graphics, if you just want eye candy then play fifa, the point of PES is to make it enjoyable, and as free/realistic as possible. Once a good patch is created this game is gonna rock!!!
Give the game a chance, it's playability that counts not first impressions.
Al