And the Sega forums poster specifically contradicts himself.
quoting from your link:
Castlevania rebirth
Contra rebirth
Gradius rebirth
Megaman 9 and 10
Rocket knight
Bionic commando
All decent to good games. True to the orginals and overall good games
I agree with him, they are all decent to good games. But then he goes on to say:
Sonic 4 however, wow. It's failing in every possible way. I have been a sonicfan ever since the beginning and I have forgiven the franchise too much. I don't know if sonicteam's goal was to please the oldschoolfans but to be honest this game is making me hate sonic period.
I don't understand how the previously mentioned games are successes in his eyes, yet Sonic 4 is a fail. Megaman 9&10, for example, are carbon copies of what sequels would look like. Clearly catering to old school fans. But then he also says that Bionic commando and Rocket Knight are good. Yet these games do a lot of things that Sonic 4 does. HD visuals, 3D models, tweaked gameplay, direct sequel (Rocket Knight is).
No, he is right. Something like Bionic Commando ReArmed is EXACTLY what Sonic the Hedgehog 4 should be. Not a remake like that is, but it takes every single element from the original and just does not change it at all. It plays exactly the same way as everyone remembered. Yes they added new guns and grenades, but that does not change how the player moves around the level - Like Bionic Commando ReArmed 2 does, which I think seems like a disaster already.
Mega Man 9 is what most people probably wanted in Sonic the Hedgehog 4, but I think this is the easy way out. Nothing wrong with that when it actually works though, everything is as the players would have remembered it, the controls are the same, the physics are the same, the music is the same... Mega Man 10 is more of the same with less passion and all, but Sonic the Hedgehog 4 lacks a lot of passion to begin with IMHO so I think they are about even.
Rocket Knight uses new art and control tweaks, but again it does not go against original design patterns. Actually it improved on a lot of things the original games had (control issues, etc). I prefer the art in Sonic the Hedgehog 4 to this, but I think my point still stands.
The ReBirth games are the best example of the lot I think. New art and graphics with new level concepts and art that fits in perfectly with the series all the long being sprited in great looking 2D like most people wanted. Not to mention a ton of the music is remixed AND all of the games are designed with Konami arcade hardware in mind, which is why it has the same sound effects... Brilliant idea. These were all done by the same people who did the cheap SEGA AGES 2500 series, so SEGA could have easily gotten them to work on a Sonic game
Something I would also like to add to the conversation is Bonk: Brink of Extinction. While the art is truly, truly terrible the staff behind it seem to really have a good idea with what the series should play like, unlike Sonic Team who think they can improve concepts with stuff that is linked to the downfall of the franchise. The game concepts are unchanged, and the only stuff added to expand the game would be as major as the different shields in Sonic the Hedgehog 3. Good extra features like online stuff (not just leaderboards) and new level art concepts and gimmicks make me think these people are trying harder than Sonic Team when it comes to Sonic the Hedgehog 4.