Each family is different and I can only speak based on my experience. We went to WL for 6 days last year and coming back again this year with 4.5 and 2.5 yrs old toddlers.
First time we went with regular dinning plan and this time going with DDP. I am not debating anyone about "worth it" or "not worth it" or "will I use" or "will I not use" --- simply its not about that.
With 2 small children - a buffet lunch in the park is almost a must - we simply needed a break from the heat and pushing the strollers for miles.
I wouldn't do breakfasts if you are planning to change to regular plan - we did one breakfast and we felt simply hungry in late afternoon after 8-10 hrs of pushing strollers
if you are going with small children - plan your days having 2 things in mind: escaping from the heat and having some breaks. again each family is different and I can share my experiences only:
1) 2 days at MK are must. my older son is not into animals and AK was almost - "mom can we go back?" you know your kids better. same thing for Epcot. He was simply not interested in WS. I am not saying I wasn't or I didn't enjoy it - my older son was simply not interested.
2) plan your park days having kids in mind. if you are going April or later - keep in mind it will be hot and you need a break from the heat. Lunches are perfect to rest.
3) since you are not on monorail line resort - plan your MK day with kids in mind. Last April - DD was 16 months and DS was 3.5 - both simply loved the parade at 9pm in MK. both kids fell asleep the minute we left the park in the middle of Wishes - but I wouldn't trade these 2 night hrs for anything in the world. to see my kids jumping and dancing during the parade was priceless. so ask yourself - wouldn't it be better to come to MK at 2-3pm after early nap, having 3 FP to be used on kids rides, and do late dinner around 7:30pm and stay for the parade?
I wouldn't survive entire day from 8am to 11pm with 2 toddlers in the park. since we were staying at WL - we simply went back to the resort from 1pm to 3:30pm to rest.
4) MK in the evening - the place is simply busy and with 2 strollers to get through the crowds - mission impossible. sure - lines for the rides might be shorter - but you can't get through the crowds with 2 strollers that easily. thats why i booked this time dinners at 7:15pm and will use 3 FP for obvious rides that my kids will enjoy between 4-7pm. once the dinner is over - we will try to get as close as to the entrance / exit of the park and watch the parade / wishes from that location. with 2 toddlers / strollers - I wanted to be on the first boat to WL.
5) HS - lunch with Jake & Sofia is a must. this time we are planning to arrive around lunch time and stay for the fireworks. we will use FP to get 3 rides and plan on watching 2 shows. dinner at MP with the preferred sitting for fireworks as the package.
6) AK day - for us on upcoming trip will be 1/2 day.
final thought: plan with kids in mind and how you can get some rest during the day. If you stay in the park entire day - plan your FP, shows so the little one can get some sleep in AC area as well as you can rest. character breakfasts are fine - but you will need break from the heat and kids - I would do lunches / dinners and plan having your family in mind.