Posting to keep track of my progress. Bought house in June 2014 for $120,000 and financed $108,000. Owe $100,728.12. 30 year loan but have paid based on 15 years every month. Have been using debt snowball and have one more debt before attacking house payment.
I love the "sign up for 30y pay it off like it is 15y" method. This gives you the peace of having a lower payment if needed, but the power to pay it off faster.
Check that those extra payments are going against the principal. (I think so based on your numbers but I'm not sure because I don't know your interest rate.)
What I love is that you cut your time in half but it is not the same as doubling your payments.
You have probably crunched your own numbers but here is an example for others:
Assume 30y at 3.5 % payment = $483
Assume 15y at 3.5 % payment = $770
Double payment 30y at 3.5% = $966 but this is paid off in 11.3y
Also, just be careful how big that other debt is and at what rate. Is the other debt CC, student loan ... If it is higher than the mortgage rate I would pay the 30y mortgage at a 30y rate and throw the extra into the higher interest debt payment first. As soon as that debt is gone then you should get back into the pay like it is 15y habit (or 10y).