The phrase "far less substantial" is correct and usable in written English.
You can use it when you want to emphasize that something is considerably less than another thing - for example, "The new car was far less substantial than his old one."
Her summer wear is far less substantial.
The critical consensus on Pamuk is undeniably strong, that on Shafak far less substantial.
With The Huntsman, he didn't have to audition: "The irony is that I've auditioned for far less substantial roles and not got them".
"An inspiration," Annacone called Andre Agassi, who has had a very different career, one far less substantial, but who has set the highest standard for physical recommitment, torturing himself running Las Vegas hills.
But Kevin R. Johnson, group vice president for worldwide sales, said that its software licenses indemnify customers against legal patent and copyright challenges to Microsoft products, whereas the legal protections offered by companies that support Linux are far less substantial.
In Latin America for example, the race to update to expensive smartphones has been far less substantial and for many users who own Nokia-built feature phones, the logical upgrade is to budget Lumia handsets running Windows Phone.
However, for these metrics there is far less available information, substantial natural variance across the region due to differences in local productivity and reef connectivity, and greater uncertainty about historical baselines.
While knowledge on factors affecting personal dignity of patients nearing death is quite substantial, far less is known about how patients living with a serious disease understand dignity.
Called to testify before uneasy lawmakers on Capitol Hill last week, Petraeus appeared far less committed to an early, substantial drawdown of U.S. forces next year than Obama... Counterinsurgency, he said, is a "roller-coaster experience" that does not lend itself to a strict timeline.
