Wow the last boss was anticlimatic as fuck, had to be one of the weakest I fought. In general I'll echo what Derkon said a few posts up, bosses are quite easy compared to trash. Probably a large part due to having played DS1 and such so used to basic mechanics but other than Mytha and the Pursuer at lvl 15, I don't think I've wiped more than 5-6times on a single boss. On the other hand some of the trash mobs kill me over and over fairly easily, like those giant knights in the dragon shrine? Sword ones are alright but halberd and 2H mace I pretty much die over and over, had to cheese them with pyromancy.
Which, by the way, is still broken as fuck. No int, still does 1k dmg per swathe, 600 per greater fireball, chaos storm on large bosses can do upwards to 8-10k depending on the boss position and what part can be hit and combustion is still one of the best "melee" weapon since it does about 700dmg with a fairly short windup, only downside is charges and range obviously. That's with a +10 dark flame and max hollow.
Anyway, finished the game in 70hours, lvl 160 and 540deaths. Only used internet for dagger locations and game mechanics or checking on stuff I had done, started checking this thread only after I was fairly far into the game. Looking into it, I missed a few things here and there, some of which I knew I had missed but assumed they would be later. Worst fucking thing though was the windmill and Mytha, that's just very very poor design. The boss is by far the hardest in the game if you don't do a completely random and illogical thing.