True i didnt specify it had to be a naked lens as i thought anyone who wanted top quality would never use a x2 converter but use the lens appropriate for the job. Sorry, for any confusion. As for cost etc, i never mentioned cost. I never mentioned converters. I'm trying to point out that the new lens to all but the most highly critical pro in a very limited photo op isnt worth the upgrade. Just like the last post, yes it has some advantages to a very small segment of the market, highly critical pros shooting in very poor light conditions. For us mere mortals we will never tell the differance. I know my friend who covers the most watched pro soccer in the world English Premier League isnt upgrading. What does that say? Hes never experienced a problem with flare and you always shoot on a monopod/tripod with a 500 due to its length and weight. 1.5 lbs will make very little differance. If im wrong then when i watch the upcoming Olympics i expect the pros to be shooting hand held with the new 500.