I just bought Dark Souls on the ps3. And there´s and update, 1.09. I was searching on the web to see what was about, and then I found soo many users complaining about it, but, those post were like from 2013. So, is ok to install the updates? what should I do? I bought the game on the PS3 cause I hated how bad works on the PC.
You don't have to worry about installing the patch. I don't know where you have found people complaining about the patch, but there is actually no reason to do so as far as I know. The latest PS3 patches only fixed bugs.
On the PS3 you only have the choice to install the latest patch or play the game completely unpatched and because the patches introduced significant balancing changes and bug fixes, it is better to install the patch right away.
Patch 1.06 included the Artorias of the Abyss DLC content, so in case you purchased the base game and planned on buying the DLC, you need to download the patch. The latest patch is also required to play the game online.
I completed the game with patch 1.09 and didn't run into any problems. You can find a list with detailed patch notes for each version on this wiki.