OK The real answer to this is really rather complicated, and takes a bit of Math.
I did a Spreadsheet with average prices based on Resorts and Seasonal rates. This is not exact but it will let you compare.
Rack Value Moderate Delux
Value $82 $149 $280
Regular $105 $170 $325
Peak $125 $195 $360
Holiday $145 $219 $435
4 day price
$328 $596 $1,120
$420 $680 $1,300
$500 $780 $1,440
$580 $876 $1,740
7 day price
$574 $1,043 $1,960
$735 $1,190 $2,275
$875 $1,365 $2,520
$1,015 $1,533 $3,045
Save
$246 $447 $840
$315 $510 $975
$375 $585 $1,080
$435 $657 $1,305
Now the Dining plan offer is worth about $40 per person per day.
Thats $280 per person
2 ppl = $560
3 ppl = $840
So if your Resort/Season saving number is higher than the meal plan savings for the # of people in your party, then take the 4/3 otherwise take the Meal plan PIP
Long story short, at a value resort with 2 or more ppl you are always better off with the meal plan. Same goes for a Moderate resort in the Value season.
For everything else, take the 4/3