Hi Allen,
keep in mind that the goal of the XIV AIM back-test was mainly to demonstrate the barbel strategy (90% cash reserves, 10% highly volatile), and to show that it can deliver equity-like returns over a long period of time, with much less risk than an all equity portfolio.
In 2011, XIV lost 80% of its value over the course of 3 months or so, so it is not something one would own much of.