using -O3 options with g++

[ami]

hi all i am new to gcc compiler. for my one of application on 64 bit
linux machine i have a doubt whether i should use -O3 or -O2 for
better performance.
as i read in documentation of gcc, -O3 is told to be higher in size
and higher in performance compare to -O2.
but -O3 defaults options enable functions with 600 lines to be inlined
and it breaks the code in huge scale. so is it ok to deliver final
executable with -O3 options or using -O2 as most favoured by
programmer earlier.

also i want to know which one is most prefered by linux programming
professional these days ?
thanks