First time i played it, yesterday, offline, made it to chapter 2 and i can say that bosses, are hard as hell!!!!
I'd love to play it online, but i don't have any friend to help me and the time difference, between Greece and other countries, doesn't make it easy for me.... 
haha, that sums up my offline run in a nutshell. Though ironically now I farm chapter 2 hard with little to no difficulty xD
Also you don't always need to run with friends, just run with the people that are online. Thats how I started, then I found a few good people I enjoy running through the game with. Im sure you too will find people to run with xD
Finally got my Alucard sword 4 days ago thanks to my luck items and dextro custos and luminato 3 days ago. Now if only i can get my hands on sinestro custos and acerbatus...
congrats on finding the Alucard sword and all the best with finding those other items

but what do those items do anyways?
I noticed that they did add one more little thing to the game for PS3, and that's a little guide with animations for each character explaining in better detail how each player plays. It's available when you chose to view more details about a character. I know a lot of people complained about how this was missing on the XB, so at least on thing they fixed one thing. They also renamed the confusing "Main Menu" to "Status Menu" (though I think "Equip" would be less confusing). Have you noticed any other minor improvements?
hmm, nothing I've noticed myself (though never played the 360 version). But there are still issues from the 360 version that should be fixed on the other hand... Btw, did the 360 version have the "stuck on loading screen" issue? I know of the issue of being stuck fighting second form dracula or dracula disappearing altogether was already in the 360 version.