Short answer: 25 years = higher payments, less total interest, own home faster. 30 years = lower payments, more total interest.
A 30-year mortgage has lower monthly payments but you pay way more interest overall. A 25-year mortgage costs more per month but you own your home faster and pay less total interest. If you can afford the 25-year payments, choose it. You can always switch to 30 years if money gets tight.
Loan Amount: $500,000
Rate: 7.0%
Twenty Five Year Payment: $3,533/month
Thirty Year Payment: $3,327/month
Total Interest25: $559,900
Total Interest30: $697,700
Difference: $137,800 more interest on 30 years