Evaporative Cooler Pads: Aspen Vs. Spongy Synthetic

The house I bought came with an evaporative cooler. I thought this was the greatest invention of all time until I lived in the house for a while and had to deal with various maintenance anomalies.  More on that later. The cooler came with aspen pads (made with Aspen wood fiber). When winterizing the system I found all sorts of aspen fibers in the basin, clogging up the pump. I thought there must be a better, less primitive material. In the following Spring, I found DIAL DuraCool pads at HD (http://www.homedepot.com/h_d1/N-5yc1v/R-100346714/h_d2/ProductDisplay?catalogId=10053&langId=-1&keyword=evaporative+cooler+pad&storeId=10051). These are basically a sponge like material. The manufacturer claims they are cooler than both paper and aspen, and can be cleaned and reused, so I decided to give them a try. They seemed to work ok but it's hard to know if they were cooler than the aspen pads since I had no measurement of the aspen pads under the same conditions (temperature, humidity). I've read that pads should be changed each year. Yesterday, being the hottest day of the year at 100F, I decided to replace the pads since the cooler wasn't performing well. This time I decided to try the AspenSnow aspen pads http://www.homedepot.com/h_d1/N-5yc1v/R-100346409/h_d2/ProductDisplay?catalogId=10053&langId=-1&keyword=evaporative+cooler+pad&storeId=10051 Interestingly, they claim they are cooler than the synthetic pads and paper. They both seem to agree they are cooler than paper but I didn't read what the paper pads claim. Hands down the aspen pads perform significantly better. It was amazing how much colder the air was. Aside from better cooling, they moved much more air than the sponge pads. Today will be the first full day test with the pads and with a forecast high of upper 90's, I'm hoping it will keep the house in mid 70's. Interestingly, Wikipedia alludes to better performance of aspen pads due to the wood fiber soaking up the water, but that assertion is flagged with a "dubious" citation http://en.wikipedia.org/wiki/Evaporative_cooler