As a manager of total portfolios, I would rather have the flexibility to adjust weightings to corporates, govts, mortgages, global, EM, high yield, floating rates etc. Unconstrained bond funds are the product du jour because they can market their ability to lessen their exposure at any given time to the downside price pressures that result from increasing interest rates. I can do that myself at the portfolio level and still leverage the expertise that asset class specific managers bring to the table. Why would I hire a bond manager to manage an equity weighting that could potentially be as much as 20%? Respectfully, I disagree, I do not believe that this will be the future of fixed income investing.