I use both. I have a canon 5d mark II that I bring, and then my iPhone is an 8+. We still have little kids (6, 4, 2) so the canon is more for character pics, and candid stuff around the park (and outdoor rides I can take pics from the ground if I'm waiting with the baby.) I have done a 50mm and a 24-70mm, I usually bring the 24-70 even though it's hefty. The iPhone is for ride pics, and times when I don't feel like getting the camera out/can't get it out fast enough.
so, last halloween we had 7am magic morning, and our party of 8 was in front of the castle with no one around. It was awesome. A dad with a stroller offered to take pics and took my canon saying he knew DSLRs. He also took some with the phone. My lens must have gotten set to manual focus, because I saw him focusing and wondered WTH he was doing, and then the pics came out where the castle was in focus but we weren't. ha. Surprisingly, the phone pics were pretty awesome. I could probably blow up to 8x10 and it would be tolerable sharpness. That's a plus though, my husband's 8 there's no chance.