I’ve been to both in the last year...Disney land is more laid back for sure, some of that comes with the ease of parking, getting in and out of the parks, hopping between parks...most of it comes from the fact that you don’t have to plan months in advance like you do at DW. If I were trying to make things as relaxed as possible I would get the max pass, we did it this last trip and found it worth the price. It saves a lot of running around at least. I do think most of the “laid back” vibe at DL was more evident to me than to my kids since I’m the one who does all the planning every time we go to DW. If you’re only doing one park a day at DW I don’t know that you’ll notice a huge difference at DL It was still busy, lines, people, noise all of that was probably similar...but since the logistics are a little more laid back, if all things were otherwise equal and I was trying for a more laid back park I would go with DL.
By far the most relaxed Disney park I have been to is Hong Kong...which probably doesn’t help you much now (not to mention the protests make This a difficult time to visit)...but now that shanghai Disney opened more of the mainland China guests are going there instead and Hong long is sooo relaxed now. It’s very small- one of the smallest if not the smallest...only one park. We didn’t wait more than 10 min. For anything, most rides we walked right on. No crowds, it was quiet, relaxed- we didn’t leave feeling like we had walked forever and overstimulated by anything, we just felt like we hung outX honestly after being used to DL and DW it kinda felt like we had rented the park out for a private event.