Let's be real though, the odds of paying it off early are less if you're not forced to. I'm going to save almost $200k in interest over the life of the loan by switching to a 15 year. Like I said, I'm paying higher on purpose, but the difference in payment is only about $150 difference a month. Did the same with a condo I bought back in 07, even though it was technically an investment property when I did the refi, my payment was about the same. The hope is that everything is paid off prior to my oldest going to high school. They all have 529's so that will give me the chance to save for a few more years and take some time off when they are all out the house.
You must have a tiny loan for the difference in payment on a 15 vs 30 year to only be $150 a month
A loan of 100k @ 2.875% has a payment of 415 for 30 years vs 685 for 15 years. The reality is that the 30 year would have a higher rate but even if the 30 year rate was 3.375% vs. 2.875% the difference is payment is still over 240 month
For my loan the difference in payment between a 30 and 15 year term is $1324 per month.
Also, I'm self employed and while I often have months where I make between 15k to 25k (had a month last year that was almost 60k) I also have months where I don't make any money so having the option to make a lower monthly payment is a benefit to me.
Finally, there are a few times per year where I pay an extra 2-4k to principal. I've done this routinely since I first owned my home. I can easily pull out my old and trusty HP12C and quickly figure out where I want to be on the amortization schedule or this can also very easily be done online.
Everyone is different but a 15 year fixed is not the right choice for my situation