Pseudo, you're a man of contradictions. You want a low-risk, guarantee on your mortgage. But you're already planning to work extra years so you can buy a Ferrari? How will owning a car that's worth the same amount as your house make your retirement less risky?
B42 already explained the math pretty well.
But here's a missing part of your thought process: you're only considering the first 10 years of the math. Have you consider how the numbers fair 30 or 40 years from now? I think you came here in earnest, so I'll take the time to post this using your figures considering a 30 year time-frame.
Scenario 1: Pay Off Mortgage Early (367K, 3.5% interest, 30 year term)
Additional monthly payment: $1,629
*runs mortgage payoff calculator* (see bankrate.com)
*result: mortgage will be paid off in 11 years, 4 months*
So at the end of 11 years, 4 months, you will have:
Mortgage loan: $0
Additional Investments: $0
Now, presumably you will invest the additional monthly payment + your normal payment in the stock market:
Additional Investment: $3,277/month
*runs investment return calculator* (see bankrate.com)
After the remaining 19 years, you'll have $1,525,048
End result after 30 years:
Mortgage Loan: $0
Additional Investments: $1,525,048
Scenario #2: Pay off Mortgage slowly
Additional Investment: 1,629/month
*runs investment calculator*
After 30 years, you'll have $1,915,810
End result after 30 years:
Mortgage Loan: $0
Additional Investments: $1,915,810
Difference between two scenarios: $390,762
***Note this is with conservative, 7% investment rate of return. If you use 10% return rate instead of 7%, the difference is $1,268,003***