Q. What difference will this make for me on the water?

A: If you are racing against someone who owes you 30 sec/mi TOD, and you sail 1 mile at hull speed (5-6 knots), you will gain about 1 boat length in time or about 6 seconds more than with the old 'Q'.
Over an hour you would go 5 plus miles and gain 5-6 boat lengths in time or  about 30 seconds.
Previously, over an hour your TOT allowance was about 150 seconds( about 15 seconds for each 3 sec of difference). With the new 'Q' you get your 150 sec/h plus another 30 sec/h or 180 sec over an hour. So over an hour previously you needed to finish inside about 25 boat lengths to win, now you have to finish inside 30 boatlengths. The additional time given  with the new 'Q' makes it fairer for the smaller/slower boats in any division.