It all depends how it could / should look like and react...
I would not say it doesn't work, it is just not everything possible.
I put an example together please downlod here:
http://jsp.logiczone.de/downloads/SimpleStarfield.zipWhat you can see are some MaxGui gadgets on top of a canvas.
When you type some text into the textfield i draw it above in the canvas again to show it working while the canvas is updated. Actually the textfield with a XP theme doesn't look too bad while before the classic mode had a sunken frame ( it's now only a small line).
Push the Start/Stop button while the Starfield is drawn, and observe your cpu usage, all events are still working.
Change the combobox to another entry to change the amount of stars.
Move the slider to speed up the starfield.
When you hit the checkbox for fullscreen it will do ...
The button on the bottom left is a SmartButton, which acts on hoover (yellow letters, sound) and left click to end the program.
This is not really a serious program, just an example, but plain MaxGui (even the SmartButton). And it may shows what i meant when saying things like sliders and comboboxes are limited to customize. Nevertheless a lot can be done.