"major distinction" is a correct and usable part of a sentence in written English. You can use it when you need to emphasize the difference between two things. For example, "The major distinction between a tablet and a laptop is that they have different designs and features.".
The Lavernes maintained that what they did -- screen-printing -- was a handicraft, a major distinction.
One major distinction between Europa-Park and many of its rivals is that it's family-owned.
To the proud Wakefield, there is a major distinction between those descriptions.
The major distinction of a game modification or remake is the technical dimension.
The major distinction between the two was Vaughan's lack of classical training.
One major distinction is a legal one, however: the Chapmans buy the art before they deface it.
A major distinction must also be made between conventional bombs and atomic and thermonuclear bombs, which have a far greater destructive capacity.
Ludwig does not simply clarify my doubts with English writing, it enlightens my writing with new possibilities
Simone Ivan Conte
Software Engineer at Adobe, UK