If your looking to get the most out of your banner file size wise, hand coding is by far the best. Program's like Edge, and GWD are great for people who want to prototype or aren't worried about file size. They typically add a lot of unnecessary ( and heavy ) code. Making something with high efficiency and performance, every bit matters, when you are pushing that limit right up to the file size boundary. Hyper optimizing your Images, naming conventions of your css, and even how your GSAP animation code is written can save you important kilobytes here and there.
Some of the same tricks we used in the flash days can still be applied, with clever image cropping and masking etc. Eventually they may increase the cap or improve these GUI's so using them is more feasible. However if you ever compare them with hand coding in the file size category hand coding always wins in my opinion. Right now that seems to be the most important aspect of banner development.