The VaR estimated using the principal mapping approach understates the true risk of a portfolio since it ignores coupon payments and any risk associated with them.

The VaR estimated using the duration mapping approach replaces the portfolio with a zero-coupon bond whose maturity equals the duration of the portfolio.

The VaR estimated using the principal mapping approach differs from the undiversified VaR estimated using the duration mapping approach due to an adjustment made for correlations.

The VaR estimated using the cash-flow mapping approach is less accurate than the VaR estimated using the duration mapping approach since it does not account for the timing of cash flows.