you dont see them around all the time, not that many people have them but they are not really rare, a lot of places prob could get them ordered in. i think they are a beautiful plec, when younger, look kinda like a Gold Nugget, and later go this fabulous yellow colour. my favourite thing about them are the fins, especially the dorsal. they look great. i'd get one if i found one in the shop i think.
Size wise, a lot of things beat them. if you like the colouring of the luteus, theres the L014 goldie, which gets to a similar size. GN's get to be a few inches bigger. then there are any number of other plecs like L025, some royals, gibbys, commons, adonis, histrix etc...