The XGIMI Elfin looks a lot like the Halo on paper, with its 1080P native resolution, 1.2 throw ratio, and 800 ANSI lumens. But XGIMI clocks the new Elfin in at $150 and $50 below the Halo and Mogo Pro+ respectively. The only thing you really have to give up for those savings is a built-in battery and a bit of oomph when it comes to the soundstage the projector provides.
Without the portable power source, XGIMI is clearly aiming the Elfin at internal use without the need or requirement to move it around a lot or use it on the road. In those scenarios, the flat design really works well as you can place it on your coffee table and not find it too tall or distracting, or have it mounted on the ceiling and still have plenty of clearance to walk underneath of it. Thus, looking at its physical attributes and price, the XGIMI Elfin is actually a more enticing choice than the Halo since it caters to a larger non-outdoorsy audience.
In terms of viewing quality, it is obvious that the Elfin is no main TV replacement—just as the Halo or Mogo series are not either. But due to the more stationary nature of the Elfin, there is more emphasis on being able to deliver a viewing experience that is good enough in a space which could be serviced by a TV instead. In that regard, the Elfin does really well in a dark environment. At 800 ANSI lumens, it is bright enough for casual viewings and would feel right at home mounted to the lower ceiling of a basement fun room, for example.