While looking for reviews (to see if there was a gameplay difference between the two), I came across this little article...
PEOWW.co.uk: The Rise and Fail of Pro Evo
The guy says PES5 was rubbish and that Seabass was a hack.

Strong words... But there's some food for thought in what he says about PES5 being (paraphrasing) entirely about passing. But still... I feel uncomfortable!!
A few days away, a lot info to catch up. First of all, without knowing much about the credibility of the author, he left me with the impression that no title of PES satisfied him. He hammered almost every title, going back to golden titles of past , that he did not mention. Also for my point of view, when you went to go to a very deep break-down analysis, you cannot ignore details. I.E. commenting on PES 5, that it is difficult to control the ball, it is 50% true. If you totally ignore the function of R2 introduced in PES 5 to receive a pass, then yes it is true, every 3rd pass you have a bad control or a throw in. But if you use the R2 as your second nature, which was extremely fundamental in PES 5, then i can't see ball control being broken. And for me , when you are a famous reviewers, you cannot ignore such details.
As for the rest series, i disagree that PES 1 to 6 was almost the same game with updates. This surprised me , since he separated even PES 6 ps2/pc with Xbox360 version. You could say that the ISS pro evo, ISS pro evo 2, PES and PES 2 for the PS one series, was almost same game with updates, tweaks and the usual KONAMIs add-remove thing, but there is an excuse here, that they were ahead of the next gen (PS2) back then, working from PES2 and ahead on two platforms (ps,ps2) like the ps2 PES 2008-2014 series are all based on the PES6 engine, with some tweaks. But in the next-gen i cannot say that PES 3 and PES 2 are the same game, without changes and or sure PES 1 is not the same with PES 3, there is a huge gap here, in innovation, mechanics etc. Maybe the speed was really nerfed, but other stats like pass accuracy, shot technique were working nice, passing with Pirlo or Sol Cambel was really something different back then, especially compared to today's precise passing from everyone.
The points i agree 100% were, lobs/chip shots being OP in pes4, the bad PES2008-2009, and the part about FIFA regressing after 2001. Here i can say FIFA 2000-2001-2002 were pretty same game with updates, it was the first time that i completely ignored FIFA titles (2001-2002), i felt dumbed as a customer, after some almost decent years of FIFA 98-99-2000. Especially on 2002 i was stuck in the past playing FIFA 2000 and ISS 2000 (N64), until April of 2002 ,when i bought a second hand PSX console and started dipping in the new KONAMI era (PES, ISS pro evo, etc)
Finally i think it is be proved by history (ad hoc) that the series did not lost its fanbase since PES 5, as it is implied the post, but since PES2008, with the simultaneous regress of PES and the rise of FIFA, cause the PES 5/6 series have a core of fans and followers ,playing exclusively them until today. The other excuse is that the article was written back in 2009, so we have an experience advantage, analyzing it now in 2019. So it is not fair to be strict enough.