There isn't one answer and it depends on a number of variables. Are you a rope-drop, stay until closing, and rope-dropping-again type? Then the Grand probably isn't worth it. Is it almost impossible to afford the hotel? Not worth it. You have the money but feel that spending it on an expensive hotel is a waste? Don't care where you sleep? Aren't planning to spend any time looking at what's there? Nope, nope, and nope again.
But I'm older and LOVE going to the Grand, especially during the holidays. I don't really go to DLR for the rides, although I love them. I like the feeling I get when I'm there, and I like being catered to for a change instead of being the one doing the catering, ha ha. I'm fine with paying more because I get a LOT more. I'm not there with kids (except sometimes my grandson), love being able to go down to the lobby from my room, love spending an hour or so in the Hearthstone Lounge, love sitting in the 3rd floor lobby having a snack and glass of port, etc. At Christmas, I can look over the balcony and watch Santa with the kids (and adults!). I meet a lot of fun people at the hotel then and often have had so much fun just interacting with others when I'm there. I love the dining options, which range from self-serve to exclusive experiences.
And the neat thing is that I can walk out the door and be in DTD. I can walk straight into DCA from the hotel. I don't have to leave the resort at all, which is something I value highly at this stage of my life.