I am disappointed with some of the responses so far.
You must have a recent w&b report anyway! (dated Nov. 2004 on the 161 I use) if the aircraft is being operated in accordance with the flight manual/ c of a, factor the temp and level and then add the caa factor for take off and landing from the safety sense leaflet, if you are also within your personal limits you go!
I consider myself cautious and like to have considered all of the available information before every flight and would not fly if anyone was at a greater risk than normal.
I don't think creative accounting, extra power, wise men or putting people’s lives at risk has anything to do with it. I was just stating a few facts regarding the capabilities of the PA28 they pose no abnormal level of danger when operated by the book.