Minimum power speed for most helicopters is around 60/70 kts, meaning lowest fuel consumption. As 212 stated, hovering outside ground effect (HOGE) uses much more power and fuel and is more difficult to maintain accurately, because it requires an instrument scan in addition to ground references. Having said that, subject to prevailing wind velocity and visual references I would sometimes prefer to hover because I could place the aircraft to face a constant direction, such as towards the airfield or another aircraft on final approach. If doing the latter, the other pilot is more likely to get early visual contact with my landing lights, rather than a nav light. If orbiting it’s as likely as not that a controller will urgently require the pilot to acknowledge visual contact with an aircraft that is presently in the 6 o’clock position! Other pilots may not be so happy to hover, depending on their personal experience.