To Dan_At_Home: The earlier you start saving for retirement, the less you have to save. Your fixed mortgage payment will stay the same year after year while your income and investments will grow over time. It's not just about killing debt, it's also about creating wealth.
BTW, I hope your bonds are short- and mid-term. When interest rates go up (and they will), bond yields drop precipitously. Anyone who doesn't understand this could experience quite a walloping. I sincerely hope this will not happen to you.
Diane C most of the time (but not always) you are right in that you will better off with keeping the fixed rate mortgage as long as possible.
Keep in mind that your approach can be hard too, i.e. when the stock market crashes such as in 2008. During these bad periods is when cash is the hardest to come by to make your debt payments. During the severe crashes is when people are most likely to get laid off, tenants are most likely to not be able to make rent in your rental house, dividends are reduced or are suspended, customers to small businesses disappear, home prices drop, and it is the hardest time to sell a home or car or anything, home equity loans or other forms of credit dry up, etc.
Thus, in my opinion you have to be mentally ok with a worst case scenario, i.e. you lost your job (during the crash is the most likely time it would happen), your investments are down 50%, i.e. you are losing, i.e. 6k a week in the market due to falling stock prices, and you have to sell some investments at a loss to make your fixed mortgage payments. If you can do this and hold on for the long term then great, however some people will panic and sell all their investments completely during the market crash. I like the paid off mortgage option because it minimizes my necessary monthly expenses to live on during hard economic times. Thus, I feel like I can take the risk better in these situations by being debt-free rather than having debt.
So yeah emotions play a part in my way of thinking, and if the mustachians have a problem with my paid off mortgage and it is not allowed in this forum, then I will go find some other financial independence blog to follow where it is ok.
Also with bonds, I personally do not try to time the market or try to guess which investment will do better than other, I maintain an asset allocation and rebalance once a year. Just because the market is "supposed" to do something does not mean it will. It may or may not, and frankly I don't care and don't have to care, that is the nice thing about asset allocation with index funds. If you read a book like William Bernstein's, The Intelligence Asset Allocator, it explains why this is the best way to invest in the market by finding some low fee index funds and do the asset allocation, rebalance once a year, and not try time the market.