Seems to be getting universal praise with little criticism. I'm not on Twitter so I'm probably not aware of some takes on it.

https://www.vox.com/future-perfect/22264520/mitt-romney-checks-parents-4200

Romney’s plan would replace the child tax credit, currently worth up to $2,000 per child and restricted to parents with substantial income (it doesn’t fully kick in until you reach an income of over $11,000), with a flat monthly allowance paid out to all parents:

Parents of kids ages 0 to 5 would get $350 per month, or $4,200 a year
Parents of kids ages 6 to 17 would get $250 per month, or $3,000 a year
Parents with multiple kids could get a maximum of $1,250 per month or $15,000 a year; that translates to five kids between the ages of 6 and 17. Very large families would be somewhat penalized, but many families with three or four kids will get the full benefit.

Just like the current child tax credit, Romney’s proposal would phase out for wealthy parents — the benefits begin phasing out for single filers with $200,000 and joint filers with $400,000 in annual income. But the phaseout would be implemented on the back end, through the tax code — even the richest parents would still get their $250-$350 per-kid checks in the mail every month; they’d just return the money on April 15. That helps ensure the benefit is truly available to all eligible people and not delayed due to concerns of “overpayment.”

The short answer is the pay-fors. Romney’s plan is deficit-neutral at least through 2025 (when many Trump tax breaks expire, making analysis beyond that year tough), and to do that he pairs his remarkably generous child allowance plan with some cuts to other tax breaks and spending programs.

Romney’s proposal would eliminate:

Head-of-household filing status, which gives income tax breaks to some single parents and caregivers)
The child and dependent care tax credit, which offers tax breaks for parents paying for child care services so they can work
The temporary assistance for needy families (TANF) welfare program, which replaced traditional “cash welfare” after the 1996 welfare reforms and is run as a state block grant
The state and local tax deduction (SALT) in the income tax, which critics decry as regressive but also provides a subsidy for blue states with high income and property taxes
Romney would also replace the earned income tax credit (EITC), which currently offers more benefits to families with more kids, with a flat credit worth up to $1,000 per working adult, with no child-related component. The EITC for adult dependents, however, would be unchanged.