Hi,
there is a great discussion on on SWR and bonds (TIPS) vs stocks:
https://investingforaliving.wordpress.c ... portfolio/
The crux of the good performance of the bonds is the variability in the value of a stock portfolio. It may happen in the first year of your retirement that stocks drop say 25%, and then you probably have hard time at your original SWR calculated income.
A disadvantage is that the portfolio is for a fixed number of years only, e.g. 20, and if you live longer you have nothing left. But that may happen with stocks also.