I have installed many shower drains over the years and have found that the linear shower drains from ACO to be best in class. I received this photo from Geoff Emmerson at ACO Systems showcasing the care ACO takes in testing it's products. These shower drains need to hold up to the abuse a typical wheelchair can place on a shower drain.
Because the drains are subjected to lots of point loads in small areas ensuring your drain is properly set is key. Point loads can also cause sub-floors to flex and strain on many types of waterproofing products. It is for this reason such care needs to be taken while designing a wheelchair acessible or no-curb shower.
ACO Testing Facility - Germany