They are wildly volatile, have not shown to outperform good long only managers over long periods of time and while it MAY bring down portfolio volatility but MIGHT also increase volatility (all subject to chance) the volatility as a stand alone can be tremendous.  Since almost no investor looks at their portfolio as a whole but rather analyzes each individual holding, the fact that it might reduce overall volatility is not relavant.  Add to that that fact that this fund has no meaningful track record, this is not a wise choice.  JMO

Oh yeah, if it is in taxable fund you can really forget about it.  These porfolios are terribly tax inefficient.