ROTSS was better than SM3 in every sense.  Better story, characters much closer to the source material, attempts at comedy not nearly as corny, even the special effects looked better.  The list goes on, but I'll leave it at that.
		
		
	 
what?
Look, if you prefer FF2, fine.  I can't change your mind.
But the things you stated....FF2 was a commercial.  It was a bottom line for 20th Century Fox and nothing more.  The screenplay was awful.  THERE WAS NO CHARACTER DEVELOPMENT.  It had about as much depth as a puddle and artistry as a Big Mac.  And that is what the movie was is a Big Mac.
I personally dislike Big Macs and McDonald's in general, but I know most like it.  But when they claim it has gormuet meats and daily fresh bread is when I just scratch my head.
FF2 was a committee film.  No more than 5 minutes of its 90 MINUTE RUNNING TIME was committed to character development.  And most of it was very cliché and unoriginal.  "Mom and dad would be so proud of you little sis," "I am going to marry the hot chick," and so on.
Plot threads are introduced and undeveloped for most of the movie and then a line of dialogue that is the cinematic equivalent of a band-aide is formed.  Reed and Sue want to leave, Johnny is sad.  Johnny messes up.  It isn't mentioned again for the next 45 minutes and at the very end of the movie "Hey, Johnny we're not leaving, after no development of why we made that decision and no moment of catharsis for you confronting us.  We just need to wrap up this plot thread that attempted to add drama."  Johnny then says "Gee golly, that is sure swell."
Or Silver Surfer.  He learned a lesson in the comics...one that you actually felt his journey through in that humans want to live.  So basically since he thought Alba was hot and she died for him, he learned "We all have a choice."  What?  Excuse me?  Sue said that line once and again a quick fix to get to the ending.
NO DEPTH.  You didn't go on a journey with the characters.  You watched them drive around a parking lot.
Fortunately it had such a smooth effortlessly flowing plot.  "I don't like you Richards.  So I'll trust a known terrorist and killer who calls himself DOCTOR DOOM to help me and the United States government over the guy who already did our work for twice without charging.  Instead I'll let DOCTOR DOOM walk around with minimal security a military bunker with world-destruction weapons in his grasp."
Oh yeah you can feel the intelligently crafted storyline.
As for more faithful to the source material....sure.  Okay.  Venom may have disappointed but tell me when he constitues a cloud.  People may dislike Raimi portraying Peter Parker's dancing as a vistage of his symbiote side.  But you feel the reasons that make him go there.  His girlfriend was manipulated (the love of his life) to leave him.  His best friend betrayed him again and you felt the anger when he nearly kills Harry, nearly kills Sandman and slaps MJ.  You see why he takes it off.  You learn why he let's Sandy go.  Why did SS save earth?  Because he thought Alba was cute and sad when she died?  That's it?!?!
FF2 is a hallow movie.
SM3 is a flawed movie.  It is uneven.  It has too many characters/storylines.  It does not flow smoothly.
But there is some integrity in it.  Raimi wanted to tell a story and he and Maguire cared about the characters and letting the audience feel their pain.  At least so did Church in it because more people felt for the most underdeveloped character in the film than the rest.  There was pathos there.  There was humanity.  That is why the whole 60 seconds Peter and Harry team up for are more satisfying and fantastic than the entirety of the FF2.
Just my opinion, though.