Like Himuro said, the game definitely feels more replayable than RE4 did, but I still think RE4 is leagues ahead overall. That opinion is not going to change.
Definitely.
RE4:
- has much better bosses, due to difficulty or the fact they're all unique. RE5's feel cookie-cutter in comparison, but maybe this is just me. I don't like the "Zelda approach to the bosses". In RE4 you use the full environment to be sucessful in boss fights but the "hit the enemy's weakspot!" is never taken into overdrive, except with maybe the final boss.
- has much more charm. "Your right hand comes off?" "Hey, it's that dog!", "Missster Scotttt Kennedyyyy", "YOU'RE small time." etc etc. Chris and Sheva are boring compared to Leon and Ashley. Seriously.
- Better villains. Salazar is the best villain in the series, screw Nemesis. He can't even talk.
- Better environments. The later part of the game would have you put in tons of tight corridors and hallways, this made fighting feel more cramped, especially against Regenerators.
- The enemies in general are better than RE5's. Navistadors, Gaaradors, Regenerators, Iron Maidens, the armour being controlled by plagas, the plagas that jump out of their hosts bodies and chase after you;etc.
- Better QTE's, especially the ones used in battle. RE5's feel tame in comparison for some reason. Most of the time they don't register or you somehow get out of the qte's zone and can't use it anyways. Notice how in RE4, not one qte is offense based unless it's a melee move or counter-attack. In RE5, there are a few moments where you use X to fire or something, and the whole package just ends up feel far more generic.
- Better death animations and gore:
[youtube=560,345]EHsHjrC6BXY[/youtube]
- Remember its series roots in horror:
[youtube=560,345]0YPW0HUpM1I[/youtube]
- A lot tougher. First time I beat it, I died over 50 times. I died maybe 10-12 times in RE5.
RE5:
- Has a better Mercs mode
- Better replay value.
- Has a better story. The trade off here is that because of this the game features honestly no cheesy moments and takes itself MUCH more seriously.
Those are the only things I can think of that I think RE5 is better than RE4 in that isn't something obvious like graphics.