There are so many benefits to having a smart meter fitted. My personal favourite is the environmental impact that having a smart meter fitted has on the planet -
Unfortunately, part of that impact is scrapping an existing meter that could well have decades of functional service-life left as WEEE. Prematurely replacing it with a newly manufactured plastic/electronic unit and an extra in home display box starts you off with a carbon/environment debt to clear.
From what I have seen the projected environmental benefit is mostly based on the display being a prompt to encourage people not to waste electricity by seeing a change from turning things off/down in the half-hourly snapshots the display can give, when it's turned on. For already energy-conscious households the scope for such waste-cutting is already limited.
Those figures in 'trees/year' also seem to rely on assuming coal and gas continues to be used rather than renewable generation replacing it, and don't make much mathematical sense. In Year 2 the benefit would be equal to the net carbon-sequestration of 150 million trees, by Year 4 300 million, and so on, with each tree increasing the amount it will absorb each year as it grows... but no real trees are involved. It's all supposed to be achieved by the smart meters.
Have you a .pdf or similar showing the working?