I personally do not care for them because I do not think they are as pretty as the other clams. They do not have the colors nor does their mantel extend past it shell. They have similar care just like any other tridacna clams. The need an established tank 6+ month stable, low to moderate water flow, bright light, calcium, alk, mag to grown. If your a newbie I'd stay away from clams for a while.
I saw a really cool one at a LFS, wanted in but got some ORA sps instead. If it is still there I will get it. They have the same care as other clams and can take less light as they are found in deeper water.
Sure they aren't as colorful, but they are significantly more rare, plus they look like the traditional giant clam like you would see in movies like the little mermaid, which is why my daughter wants one.