Wheather over or under clocked doesnt matter
it is just for caution
it htc evo 3d is running on 1.2ghz means it is giving 1.2 power but it has capacity of 1.5ghz thats it
search on youtube nokia 5233 over clocking 800mhz tak overclock kia hai banday ne
1.5ghz over clock ho sakta hai 1.8ghz bhi per us k baad heat up issues b ho sakte hai gurantee nahi hoti is liye
htc ho yaa apple ho yaa samsung sab ko safe side pe rehna hota hai
even 5mp 10mp arent true megapixels 19-20 ka farak hota hai:)
some custom roms over clocks processors too thats why we get more speed etc etc but there is a limit