My DW used DAS after a long-term medical event in 2015. Were cleared to go to WDW in 2016, and had no problems getting or using the DAS in 2016. In 2017, we had a poor experience with the CM issuing the DAS: the tone seemed to disbelieve our claims and experiences, I think in part because the specific accommodation was unusual (post-medical event, she has trouble waiting in dark spaces for long periods of time because her eyes adjust substantially slower than most) and in part because she presents as fully functioning. I know I was taken aback by the substantial skepticism in CM's tone.
As a result, we stopped using DAS after our 2017 visit (while she has recovered some, there is still substantial difficulty, but I can't talk her into it), and we now just book our FASTPASS+ rides differently (we are probably among the few people who use a FASTPASS+ on the Epcot Nemo ride, and while often the lines are short enough where it would be unnecessary, it's a must-ride for her and we'd rather not chance it).
There was definitely an advantage piece (how much is debatable) to the DAS: we were able to use it for Frozen (which is about the boundary of uncomfortable for her these days) about a week after it came out and ate dinner during the queue of about 150 minutes. For any new ride like that, I can't see how they could make DAS a completely equal experience, and it's probably the most reasonable compromise they could come up with.
As far as the case goes, I've been following the case on the multiple threads here about it, and I think the plaintiffs are unreasonable. The DAS system is imperfect, but pretty reasonable, and at least as far as our experience goes, the only thing that was really needed was better CM training.