Mom of 5 here- I have stayed here once a few years ago. My kids were small at the time. Youngest was 1 and I think oldest almost 9. We definitely took mid-day breaks. We never look at it like a time-waster, but that's because we do like to be in the parks for rope drop and also in the evenings for the nighttime vibe & when it's cooler (we are usually there in the summer).
We usually leave park around 1pm and then head back for 4:30-5pm and spend the night there until closing (often sticking around for the kiss goodnight at MK and taking our time exiting to avoid crowds). We only do this successfully if we plan buffer/pool days in between our park visits. It would be impossible to be at MK for a 9am rope drop, be up until 12 am, and then do it all again the next day with small children. They need a recovery day in between.
But, to answer your question-- it's not a time waster, especially in the summer. That break in the afternoon can really salvage the rest of your day and make it so much more enjoyable. Having a dip in the pool, a change of clothes, and an hour resting on the couch in the A/C, (or napping for the little ones) elevates everyone's mood, patience and energy level for an evening back at the parks. It also saves a little money since you can eat a big meal back at the condo.
My only complaint about WBC was the parking late at night. My husband would drop us off at the door and since it was late at night all the kids would be asleep in the car. I had two double strollers since we have so many kids lol and my oldest would have to wake up and push the other stroller into the elevator and down the long hallway to our unit while my husband drove around in circles looking for parking late night. We were in building 5 and I think the garage was over at a different building so he would ultimately end up there and it was a production late night. We have not had to deal with this at any of the other condo places we have stayed (Royal Palms, Vistana, Windsor Hills). It's the one big drawback of this place!
Have fun!