@alfkil
I tried Spotless when it first came out, but was unable to make it do anything useful, not even as much as DB101. I was
left with the impression that it was mainly a demo of how to make a debugger, and that it wouldn't be developed further. Given that, it seemed pointless to try to do anything more with it, such as submitting bug reports. Has the situation changed?
I think there is a place in AmigaLand for both GDB and a working version of Spotless. Kas1e is right that GDB has far more people working on it, adding new features and honing the existing ones based on lots of real-world use. And for some applications remote debugging is useful or even essential.
Spotless, on the other hand, has a nice easy-to-use GUI and feels like an Amiga program, and could be a better choice for beginners and those with less demanding needs (and who aren't already familiar with GDB and how to use it). Spotless could be the debugger of first choice; if it can handle your debugging task, great! If you need more power then move on to GDB.
But Spotless needs more work before that's viable.