Take it to the Limit: Rounding Off Our Killer Sudoku Run

Today's Puzzle:

Did I mention that we were on a Killer / Classic run? Here is another slightly more difficult one, though the constructor does lead you by the nose through it!

Link to Play Along:

Take it to the Limit by PDN http://tinyurl.com/SudokuSleuthTakeItToTheLimit

Rules:

Normal sudoku rules apply.

Digits in a cage must sum to the little number in the upper left and may not repeat in the cage.

Numbers outside the grid indicate the sum of the digits on their indicated diagonal. Digits on these diagonals may repeat when otherwise allowed.