Okay so I've tried testing the stable version of apc and it gives segmentation errors with PHP 5.4.x branch and it seems there's an APC beta version out on PECL. I searched the internet and realized it was really hard to find the command to install the beta version so I'm posting it here in hope that it helps others
Firstly, if you built your own php, you should got your php's bin directory and type
./pecl install apc-beta
Of course, if everything goes well, it should compile and you'll need to add the 'extension=apc.so' to your php.ini file. The file for me is located in your php's lib directory. If the file does not exist, you can create it there (if you compiled php from source like I did).
REMEMBER, you may need to restart your apache or other webserver and also phpfpm if your setup is like mine
ALSO, I noticed that with APC installed and in use, more memory was used up. Like about 150 MBs extra.