For you users of image editors like Photoshop or GiMP, you guys are used to the huge memory requirements and delays of processing, and I can understand your needs for more powerful platforms. I feel I am spoiled using vector applications, like mine program of choice, Xara Xtreme Pro 4 (Xara Designer 6 is current). Vector applications don't require the massive memory requirements for graphics processing. When I apply any process while working with vector graphics the results are almost instantaneous - to the point that when I use any image editor (usually Photoshop) I am constantly derailed from my normal process having to wait for the file to update as I apply any technique. When I create a huge map with lots of layers, the file measures less than 20 MB, even for map dimensions such as 36" x 60". When I export that to an image format, the file can get huge - hundreds of MBs in size.
Another image editing weakness (IMO) is the requirement to set the pixel resolution up front, as you are defining the dimensions of your file. In vector apps like Xara, I determine real world map size, such as 24" x 36" with no consideration of pixel dimension - that only occurs at file export. Any map I design, I can export to 300 ppi resolution at true scale, or reduce an image for letter size PDF format, at 96 dpi. I expect instant results while working on the map. Any post design alterations of the image file can get huge and take time to process. While still in vector format, map creation is fast and fairly low intensity to your computer processing.