I too like the way Quilter's World does it. When I subscribed I got access to something like 12 years of back issues. Was able to download all of the issues as PDFs that are stored on my own computer.
I looked at the Quiltmaker website and it looks different. For one thing, you have to log onto their website in order to view your digital issues. Also, the photo of the digital magazine looks more like Zinio than a PDF.
Every magazine seems to use a different digital format. Decided I don't want to fool with all of them, so will stick with PDFs I can download to my own computer -- which so far is Quilter's World and Quilting Quickly.