i've heard that side blowholes really disturb the airflow of the casing.. that is why casing that have side blowholes usually have the "hood" or "funnel" that supplies the fresh air directly to the cpu's hsf.. so i guess if you want to use the blowhole, its better to a hood

guys, which fans are quieter and pushes more air?

-smaller blades but many of them (example 11 blades) or
-bigger but fewer blades (the standard 5 0r 6 blades)

Also, it is my understanding that bigger fans are able to run at lower speeds but pushes a higher volume of air and creates less noise as apposed to their smaller counter parts. Is this correct?

If this is true, i currently have 2x120mm fans that are installed at slots that are also able to support 140mm fans. Should i make the upgrade?