Here's an example to illustrate the strengths and weaknesses. The biggest weakness is that it doesn't support prose very well, so it doesn't double as a blog post or as a full lab notebook that can communicate the story of what is happening to someone who doesn't already know. The strength is in the sheer amount of stuff I am able to document with extremely little effort: physical layouts, circuit structure, instrument setups, probe configurations, and results across a bunch of devices ranging from the 68000 era through x86 and ARM. Consider the number of diagrams I didn't have to make, the number of screenshots I didn't have to schlep, the number of measurements I didn't have to export, import, format, and describe. I just point my iPad, tap, and scribble.
Making a proper lab notebook for this little repair exercise would have doubled the timeline. In academia, the need to communicate would have justified the time investment. For someone who just needed to generate a 2GHz pulse modulated clock and had a broken signal generator, quick & dirty won the day.
Needless to say, I'd like to have the best of both worlds, but at the moment I regularly put up with the weaknesses of snap & sketch because its strengths are so important to me.
