We both have pensions and elected to have no withholding. We have to make quarterly estimated payments anyway due to rental income, investment activity, and Roth conversions in December. So it's no incremental effort. Plus I like to pay the IRS the least amount required, at the last possible moment. We always owe an amount in April, which just barely avoids a penalty for under-withholding. And I frequently use the annualized income method due to large Roth conversions in the fourth quarter.
There are no forms or quarterly filings. I use IRS Direct Pay, which is just like a bank transfer and takes maybe 2 minutes. You can also sign up for EFTPS and schedule your payments in advance.
I must admit, updating my tax estimate spreadsheet every quarter is not a barrel of laughs. But we have enough moving parts that it's a necessary planning activity, especially in 2018 with the tax law changes.