I'm not a huge dining plan fan myself.
Some people in the office swear by it, one said to me she wouldnt think of disney now without the dining plan, so it works for some folks eh?
I think she likes knowing that everything's paid for up front. In terms of having to make reservations, sadly nowadays, we've founde we have to make ADRs for everything we want months in advance to be sure of getting them anyway.
However for us, its value seems limited. We never used all the counter service credits so they were wasted. We used 2*credits for the nicer restaurants which ended up meaning to be honest, with 4 credits spent between us, we could've paid for the meal out of pocket anyway!
We prefer the Tables in Wonderland card which gives 20% off everything including alcohol
Even when the dining plan is included "free" we've sometimes ignored it because having to pay rack rate for the rooms has outweighed the benefit of the plan!
No qualms with those who love the plan, each to their own, but I just don't think it's the slam dunk absolute bargain which people tend to suggest