Incredibill has a point in all of this and judging by the thread titles on this adsense forum lately the mood is running very negative, probably the most negative I've ever seen. Circumstances lately with both Panda and now a serious drop in eCPM have me looking at my secondary advertising network with more placement and hope than I've ever had before. At this point, I'm looking for stability more than the big paycheck and this other network has been giving me that more than adsense.
In regards to: >>The ads are a detriment to the site and negatively impact the user experience.<<
I use adsense and did quite a bit of A/B testing involving ad placement and number of above-the-fold ads.
I found a pronounced direct correlation between prominence of ads and bounce rate.
Me personally, I'd rather have a little more traffic and better stats than a little more income. If not already, there has to be a time when Google factors in bounce rate with the SERP ranking calculations.
The last summer I've started a few websites from scratch where Google bot is banned in robots.txt and ads come from other ad networks than Adsense and I can't believe how hard is to make a cent outside the Google atmosphere.
I remember there was once upon a time when Yahoo! and Altavista were the kings and making websites was simply fun but I feel that I would need 96 hours a day just for work if Google and Adsense dissapear.
Worst part of this history it's I think that's slowly happening; milestone after milestone.