I guess each case may be different but this is what it is for a spouse who is 3 years older than the husband. These are not actual numbers, but close.
She draws on her own record at 62 (300 a month).
Husband draws on his record at 62 (1000 a month), she gets kicked to 500 a month.
At age 67 husband withdraws application and repays his benefits and the additional benefits she got (extra 200 a month) (with her concurrence, of course).
Husband then files for benefits on HER record and gets (150 a month). 1/2 of her revised benefits after pay back. (not much but, for now, pays Medicare Part B).
At age 70 husband applies again under his record and gets benefits (1,600 per month). Her benefits are then kicked to 800 a month (1/2 of his full age 70 benefits).
Benefits received before age and after pay back 70: Spouse (300 a month to husbands age 70 or 10 years at 300 per month = 36,000. Husband 10 years at 150 per month = 18,000. Total benefits 54,000. Combined Benefits from age 70 forward = 2,400 per month or 28,800 per year.
Since there is a pay back amount to be considered (approximately 72,000 in this example) along with CPI increases over the 8 year deferred period at about a 3% compounded rate and the lost income on the 72,000 for the deferred 3 year period (husbands age 67 to 70) it appears the payback period would be about 5 to 7 years. So if he lives longer than the payback period OR she lives beyond his death she would gain substantially if she lives about 3 years longer than he does.
I think this is a far greater deal than a SPIA since it is COLA'd and has a 50% survivor benefit (If he dies first, in this case, but in all cases if the higher benefited person goes first).
All dollars are amounts are kept steady just for explanation purposes, as time goes by they would get substantially larger.