Thanks! I'm pretty happy with the improvement I've made in equipment and technique since my last attempt on this object back in 2008. The H-alpha filter helps immensely, as I was actually shooting through thin high clouds by the end of the night but the filter is so deep in the red part of the spectrum that it helped cut through a bit.
I blew most of my budget in mid 2008 getting the camera and the filter wheel, so I went with Optec filters which were 1) in stock where I bought the camera, and 2) half the price of the higher end Astrodon filters. The H-alpha filter is 8nm FWHM, which is a bit wide (I get slight gradients shooting near the moon). I hope to eventually get something in the 3-5nm range for better contrast when I have the money.