Scenario on the 30 year term: You die the day after the term expires. You've invested $225/month in a 401k at 7% annually during that time. It's valued at $255,000. The biggest benefit of SBP IMO is that it is inflation protected so it grows at 2.5%'ish/year. $255K in 2044 will be worth a lot less than it is today.

Scenario 2 on 30 year term: You die the day before the term expires. You've invested $225/month again. Your spouse then has the $255K and the value of the term policy ($500k??).

So again, which is better? I'll tell you after you die.