the stage 3 heads are not for daily driving IIRC. the cam profile especially, is not for anything other than competition. which short block are you looking at? the stage 1 is pretty much factory with a few bonuses. the stage 2 is N/A only because of the compression ratio. the stage 3 is high end turbo ready but, i couldn't tell you much else.
this is only what i remember and i may be wrong. read the fine print on their site and/or call em up and find out what would be best for you.