Yes, we both are.
I retired at age 59 but don't plan on taking SS till age 70 (primarily for the benefit of DW).
DW retired this year (64) but will be delaying SS till FRA age of 66.
Since a great deal of our retirement assets are in tax-deferred instruments, it allows us to reduce our respective portfolio's, which in turn reduce the amount of "excess" RMD's at age 70.5. Excess RMD's mean withdrawls required by tax laws, not necessarily that we need the money.
In addition, it aids a bit in portfolio management since we will be "trading in" a good portion of our portfolio for a future inflation adjusted lifetime annuity - AKA SS.
Just remember that under this scenerio you can't necessarily go with a measurement of the 4% rule. While our withdrawls are higher than 4% at the current time, it will drop to just over 2% of the then forecast value at our joint age of 70 - after two small pensions (DW) and our respective SS income flows start over the next five years.