For #1+#2-- I'm also a convert, which is sadly still not as prevalent in my field (computational science) as it should be. I always tell people: its a good 10%

For #1+#2-- I'm also a convert, which is sadly still not as prevalent in my field (computational science) as it should be. I always tell people: its a good 10% extra overhead you add to a project during design to be careful with regression testing and source control, and that is paid back many times the first time you avoid a dangerous bug or bad tarball that goes undetected for 3 months.