I usually find extensibility a kind of Turing-tarpit of distraction. You download extensions, try to configure them, get a good flow through them, etc. You have to try extensions, find good ones, and replace them as old ones stop getting maintained. You have to upgrade extensions, deal with breakages, and so on. They frequently don't have the same quality as the core, and bring their own bugs/problems along. When I have extensibility, I mostly try not to use it.<p>Mostly, I'll take something that packs a decent amount of what I'd want into a first-party integrated package and live with it. On the other hand, I don't mind opening a terminal and doing an in-place transformation on a file with perl, or opening vim/vi on a file, doing something, saving it, and coming back to my original editor to say "yep, load those changes from disk."<p>Syntax highlighting seems overrated to me. I haven't really felt any functional difference in how well I parse things either way.