There are all sorts of things to applaud in this approach.

"we have simulated the effects using a model built on a standard neo-classical growth model"

Hooray! The "standard neoclassical growth model" is exactly the right building block for this sort of exercise, one that has pretty much taken over all academic tax analysis for the last 20 - 30 years, but has been virtually absent in Washington, still using Keynesian macro models from the 1960s. What does it mean? In general, we model households making decisions between work and leisure, consumption and savings; we model businesses making investment, hiring, and output decisions to maximize profits, and find the equilibrium.

The general consensus, even from (sensible) Keynesians, is that this is the right sort of model to use for long run -- several years -- analysis. It's the benchmark model in which margins matter, in which lowering tax rates, while getting rid of deductions so you pay the same taxes, can possibly have an effect. The Keynesian models, which I criticized here also pay no attention to margins, and so assume away the effects that a reform focused on lowering marginal rates is trying to achieve.

"This model produces a simulation of what the policy change would do to the economy, incomes, and tax revenues after all economic adjustments are given time to work, which is roughly 5 to 10 years. It does not show the annual progression, year by year, from the starting point to the final outcome, but most of the effects occur within 5 years."

More hooray. Nobody knows the exact adjustment path. The point of tax policy is to get things right for the long run, not to try to manage the year to year. So don't even try to produce numbers that we all know are meaningless.