all rays are about the same to take care of if they are healthy and feeding when you buy them apart from flower/tiger
motoro have lots of down sides a male will kill a female when he is ready to breed
motoro are a bit more aggressive compaired to other rays and you have more chance of them eatting tank mates
rays in general are not that hard to take care of as long as you have enought filteration and you do at least 2 x 25% water changes per week
people just panic if their rays dont eat as well as normal or dont move about much for 2 days then they start messing with the water which afects the PH
keep your PH stable dont worrie to much about nitrates its near imposable to keep them real low in a ray tank
people always say retic/teacup are hard to keep well thats the 1st ray i ever brought and knew nothing about rays and their was no internet to get advice my tank was lucky if it got a water change every 2 months they did great for 3yrs+ then i sold them
keeping rays is easy if you have the time to change the water tank space of 30inch wide x 72inch long min and you dont panic they are no harder than a discus to keep probably a lot easyer than discus