Canvas is free software, Instructure's main value add is a 24/7 support desk, operational expertise (not needed for small scale users) and custom software development.

Compared to Pearson's crummy web learning platform and the mess of perl that constituted my college's homegrown infrastructure, Canvas was the bright spot where when things went wrong you could get ahold of someone technically competent and helpful at 11pm the night before your test on Saturday.