I believe there are managed payout funds that try to run you out of your money by a target date as well as others that try to return at a higher rate while sacrificing principal. Vanguard may not have those, but I think there's a wide variety of options out there.
With the Vanguard fund, they set it at 4% so you will almost certainly have enough money for 30+ years. Nothing stops you from selling some of the fund every year if you want more than 4%.
The point is, you have more control, more upside, way lower fees, and hopefully will automatically track with inflation...all of which you might sacrifice with an annuity.
Details could run the gamut from anything all the way up to full disclosure of account values, desired incomes, etc. All depends on how comfortable you are. Like someone suggested, posting that level of detail on the bogleheads forum might get you super valuable feedback.