The reason for the short run is because this was really a test of using a separate guidescope on the Edge11 instead of the usual Celestron Off Axis Guider. For this test, the mount was guided by the Lunt 80mm refrator I'd been using with my NP101is for wide field imaging.
Based on the results seen here I decided that the test failed. During the imaging run the PHD autoguider graph looked really good, but in the final image, the stars were no where near as round as I wanted them to be. I think the problem was that the Lunt has quite a bit shorter focal length than the EdgeHD and as such it could not really keep up with minute changes in position that the Edge can pick up.
I do have a 900mm Vixen and a barlow so maybe that will work if I choose to continue this experiment. Not that there's anything wrong with the OAG mind you, it works very well indeed. Its just that I've found its easier to run the guiding from a separate scope and wanted to see if it was practical to combine the Lunt with the Edge (it isn't).
Guiding issues aside, based on other images of this galaxy I've seen, it looks like a really good picture of the Deer Lick will take a very long run of exposures to get enough integration time. There is also some dust or IFN between us and the cluster so it's tricky to get the colors right.
UPDATE: Some time after taking this image I did try using the Vixen A80Mf refractor with a barlow as a guidescope. It works really well and I've been successfully using it ever since. But to get it working I needed a better guide camera too. The SSAG guide camera used on this photo just isn't sensitive enough to work at f22 so I ended up getting a Lodestar guider to replace it.
LATEST UPDATE: I'm back to using the Lunt as a guider. With the LodestarX2 camera and a modified barlow it now gets an image scale close to 1 arc-second per pixel. This works really well and takes care of the problems encountered while taking this image. It's also shorter than the Vixen and has a better focuser. Plus, the stars look better (ie: nicer, cleaner star profile in PHD) and it seems to guide a bit smoother and more accurately than the Vixen did.