I have both and they are totally different boards.
The shapes are different, fins size, their size, nugget is 5' the sector 54 is 5'8" aprox
when you use them, your foot weight distribution is different.
Both are great boards for their target market.
The Sector 54 is more oriented for ultimate light wind and free race you would generate more
speed with the Sector 54. The nugget is a light wind board for the waves but can't compare
to the sector 54 as a light wind board. The sector 54 main target is not to use it as a board for waves. The nugget is not the board to select it as your lightest wind board is a board for fun and freestyle .
As nobby raish mention, kind of apples and oranges.
If you are looking to buy one of them first need to decide the primary use of the board.