I'm not a heavy user of debug features, but the few times I've used it, I've found it helpful. A worthwhile feature in general. I wouldn't characterize it as a particularly intuitive a system, but I could get over that by more use and familiarity.
If I were to critique a personal negative aspect, it would be the loss of full line highlighting by clicking at the line number bar. I always liked being able to do that. I could easily make multiples of code lines, make small changes in each and then comment toggle among them. It's gone now, which I found an irritation.
As it is now, I have to be very precise with my mouse dragging from column 1 of the line I want to column 1 of the next line, to highlight a code line for cut/paste ops. My hands are those of an arthritic farmer, not a surgeon, and I have to maneuver very close to the line number bar to do this and If I'm not careful, it's constantly asking if I want to add $DEBUG, which I then have to cancel. If I actually want $DEBUG, I can go do it manually. The auto add part of it, otherwise, interferes with my workflow.
PS I see from an earlier post how to turn off the auto add feature, which helps. Still I can no longer single click to highlight a line. I suppose I better hang on to 1.5