OK...I am speaking from experience here...my dd9 has ALWAYS eaten what grown-ups eat starting around the age of two a chicken nugget has not passed that childs lips (by her choice)!

However, eating off the adults menu I find that it is far too much food for her to consume (yet...we get room discounts not free dining) to make it worth the money and with eating appetizers she is not super hungry when her meals arrive.
Knowing this...you can clearly understand what a horrible time she had being restricted for years (we've been going since she was 5) on the
DDP/DlxDP. While I don't really want to pay the cost of an adult park ticket for her yet, I have insisted she use the childs dining...it has truly been a difficult sticking point and she has truly had a trying time of it.
However, we began the practice of ordering an appetizer she is sure to truly enjoy such as Shrimp Cocktail or Calamari or any such thing. We all eat each others appetizers. This led to ordering entrees she would enjoy (as well as ourselves)...I have her order things like fruit cups and things we would eat as well. This way we can also enjoy her meal if she eats mostly from ours. It works!!!!

Everyone is happy and DD9 is able to enjoy the variety we all have. Nobody has ever told us we could not let my DD9 eat off our plates or tha we were not allowed to share our appetizer with each other...that would be like telling people they could only eat their meals with their right hands and drink with their left hands.

You buy it..you eat it how you want.
I guess you could call it Family Style.
Now a word about the buffets...my DD9 has never once been told or directed to ONLY eat off the childs buffet area. While I do know that many children only want chicken nuggets or pizza, that is not my child. However she does not eat more than a few shrimp and some potatoe salad. Plenty of WDW staff has seen her eat from the adult buffet and never says a word otherwise...I personally don't care one way or the other when it comes to a buffet.
Honestly, she has adult tastes with a childs stomach...she just doesn't eat even close to what an adult does.
Sooooo...after all that

...if you feel it necessary to get your child the adult meals (even if he will not eat more than a few bites?) and don't mind the cost, then do so. If however, you are willing to share with him so he can have more variety AND are willing to occasionally get his input on what he would like to try (for your entree) then don't.
Sometimes, I know that having more than one child makes the decision more of a struggle because they always want what each other has. If $25 a day avoided this...I would probably do it if I had two children!!!!


I do like a PPs suggestion of just ordering something extra OOP for him if he wants the variety. Many younger children are just fine and dandy with the childs meals...he can even get a Make Your Own Sundae!!!
It's all a matter of how you feel it will work for you and your family.