This is my opinion:
I'm a PC gamer, I was ALWAYS playing FIFA but I've learn about PES from PS users... and since I've play PES, I NEVER STOP! I'm spending 4-5 hour per day playing PC football (and 1... in "real life"! Hehehe...), since... FIFA 95.
Now... about "07" versions of both of them...
Both having "+/-"...
Lets talk about FIFA 07 first...
FIFA 07 trying every year to be better and compare/"HIT" the "opponent" PES. This FIFA version, has a VERY injoyable "Manager Season Mode" (like ALL "E.A." games), which is a nice "combination" of "Football Manager" and a soccer game! I LOVE that FIFA07's feature...
The FIFA07's GAMEPLAY & DIFFICULTY is... for kids. Funny to play with, but... for kids! If you WATCHING CAREFULLY the PC's players movements, you will soon EASILLY find out what's the PROPER possition that you must move YOUR player, STEEL the ball "nice+easy", proseed to the attack (ALSO nice+easy) and... if you have a great player like STEVE GERRARD (I'm playing with "LFC" club - of course!)... you shooting the ball and the keeper NEVER understanding WHEN he gets the goal!...
The SOUND in FIFA07, is great! I LOVE to be in the main "Manager Season Mode" screen, and listening... "Liverpooooool!" & other tunes from REAL "LFC's" audios!... In game, SOUND is still nice...
The LISENCE issue in FIFA07... WHAT CAN ANYONE say about that??? You can play with ALMOST ANY club/team you like, with the RIGHT rosters and kits/badges/logos... PERFECT!
The GRAPHICS' issue in FIFA07... Well, I think I'm playing the VERY SAME game, since... 2002! The players' 3D models (EVEN in the VERY HIGH resolution - I own a PERFECT system, last generation "state of art")... are REALLY "poor"! The team kits/logos are in LOW resolution! The pitch is an "OLD TIME CLASSIC" graphic-resualt, NOTHING to telling you that this is a 2007 GAME DEVELOPING! The fans (growd) IT IS a 3D model-block, but NOTHING spacial indeed... The nets, STILL looking "strange"...
Generally... FIFA07 is a funny, ARCADE, kids' game! I DIDN'T remove it from my PC, 'couse I LOVE the "Manager Season Mode"!
Now... PES6!
The GAMEPLAY of PES6... By FAR MORE realistic of FIFA, with GREAT "A.I" of PC's players (they KEEP doing SEVERAL DIFFERENT moves and you CAN'T figure out what the hell is going to do!), LOTS of different moves to make, better (I think) "long pass reseaving" chances to score, a BIT EASY to play in "Regular" mode (I think is the *** mode, of the PES5), a BIT EASY to score from distance (with STEVE-lad, naturally! "Reds" kicking ass from distance in PES6!), a VERY SENSITIVE "shooting" button (you must... TOUCHING it like your... girlfriend's "kitty"!!!) because you'll send the ball to... Mars! Steeling in PES6 is a DIFFICULT thing, but FAST-PASSING isn't so! The "long-crossing" pass is FAR BETTER now, the "free-kicks" too... LOTS of new animations have been add on the players and gives you the exprassion of... WATCHING a REAL game (I was playing using a projector screen and my wife thought... I bought "NOVA" satelite system and watching "Premiership")!... My opinion, PES6 is the BEST football SIMULATOR in market!...
The SOUND issue in PES6... The sound is very nice indeed, but... COMPARING with FIFA's,... FIFA has LISENCE from any club and is using ORIGINAL sounds! So, in PES6 the sound is great but... NOT ORIGINAL! That's makes me sad...
The LISENCE issue in PES6... This is the DISASTER for it! STILL... VERY POOR lisence's options! THERE ISN'T in PES6... Germany's Championship!!! HOW THE HELL DID THAT? I'm NOT a fan of German football, but it STILL IS one of the BEST in Europe!!! What crap is that?
Also, even if PES6 HAS the "Premiership" or the "Premera Division" or the Italian Championship... there are EXTREMELY VERY FEW "lisence" teams! And... EVEN these, having SERIOUS wrong data! For example... play France vs. Italy (the last World Cup Final) and watch... ZINEDIN ZIDAN to kick-off the ball to Henry!!! JESUS!!! The man is retired! Why they STILL HAVE him in the team???
The GRAPHICS' issue in PES6... The 3D models of the players are HEAVY-ROCKING!!! Very nice models indeed!... The player faces are BY FAR BETTER than FIFA's, but some players' faces NEEDS to be changed... The pitch... is PATHETIC! To me, a LONG TIME football gamer, THAT pitch "takes me back in time"! They COULD create a BETTER pitch... The stadiums are FANTASTIC (NOT TOO MANY, but great to watching them!)... The fan-growd... IS THE MOST PATHETIC EVER SAW, in the last 5 years!!! NO 3D "close-up" scene in the beggining of a game or in a goal,... and the crowd IN the game looks like... SMASHED TOMATOS! The MOST UNBELIEVABLE thing that PES6 have inside this new version! The nets are a BIT better than FIFA's, but OF COURSE NOT that good like PES5's!... The teams' kits... OK, we know that PES6 DON'T OWN too much of lisence, right?... Oh yea?... Go and check... MANCHESTER UNITED's kit or ARSENAL's kit!!!... The ULTIMATE PATHETIC kits I ever saw!!! The resolution of the kits/logos/emblems... are probably... BELLOW 72 pixels!!! The skins/textures of the teams' kits, are REALLY SUCKS!... I REMOVED them all and I've spend the WHOLE weekend, to CREATE "custom" (but CLOSE TO "REAL"!) kits for EVERY "Premiership" team... to makes me feel better and start a new "LEAGUE Mode" and play!...
Generally... to me PES6 is BY FAR BETTER game from FIFA07... but BY FAR WORST of a... patched PES5!!! I didn't REMOVED my PES5 with ALL these THUSANDS of patches that I've install into it,... and I'm founding VERY DIFFICULT to leave aside PES5 to play PES6!!!
Probably, after some... months that a GREAT patch will be available for PES6, I'll start playing ONLY with PES6...
For now... the PES6 is ONLY to get practice in the new gameplay!...
That's it... That's my opinion...
Cheers mates.