The cast here is uniformly attractive and the setting is one of those mansion wannabes smelling of new money. The angles are calculated to maximize both the action and the reaction, so to speak; a craft unto itself, which few master.
Sexually, it's not exactly the nuclear-grade, oiled-up rectal inspection that some viewers can't seem to live without, but rather a sultry exercise worth a hearty recommendation. One highlight is the scene with Regina and Alaya, which builds to a scorching climax as Alaya leans over a couch, doggie style, while Regina plows her with a dildo. Also noteworthy is a bathtub grope between Mariah and Taylor.
Indeed, if fault exists in NML:IR4, it's the reliance on toys where tongue and finger could've sufficed. A minor quibble.