I am still collecting data on NGC55 and I thought it might be interesting for people to take a look at two images of the Ha.
One is at 5 hours and the other is 27 hours.
On first look it does not appear there is much change but once one starts taking a closer inspection you'll see there is some dramatic change. There are arches, bubbles and knots all the way along the galaxy. Also some of the darker regions are now showing quite a lot of detail. I am really impressed by the arches. Some more hours to go yet, mainly to see what becomes more visible.
As you say with an initial look they are quite similar but on closer inspection the details are significantly sharper. It takes a lot of hours to get that improvement.