About article - a good one, well written, nice to read.
And cooler - in my opinion in this case you pay $50 for the best cooler for this card.
5*C difference compared to already modified copper-based heatsink is a lot in my opinion. Memory OC difference is also noticable, looking at users opinions. I wouldnt be suprised to see >10*C or even 15*C+ difference comparing to stock cooler.
$15 for ATI Silencer - nice find I'd say. Unfortunatly there's no Silencer for 6600GT AGP.
Is this cooler worth $50... It probably is. Personally, I wouldn't buy it, because I haven't got that much money to spend on GPU heatsink and I can do some modding and I have tools. But for people who look for performance and don't want to use CPU cooler, Stasis seems to be a very good option.