I have an SPIA, purchased when I retired just under three years ago, at age 59, with 10% of our then combined retirement portfolio value. It was a key component in our decision for me to delay SS till age 70, primarily for the benefit of my wife. In other words, it acts as "gap insurance" for an early retiree who is not eligible for SS at retirement, and wishes to delay SS even if eligible.
It is for a 28-year guarantee period, and payments continue to my DW if I pass first. If either, both of us live beyond the 28 year period, payments continue at 100% for the rest of our lives.
If we both pass before the 28 year term ends, remaining monthly payments continue to our estate (trust, for the benefit of our disabled son).
We intend to also buy additional SPIA's in the future as we age and don't wish to manage our respective portfolios to make things a bit easier.
For us, it was a good decision and only for our situation. For others? They will have to "do the math" to see if it makes sense...