I've been using the new Nextbase Reflection Free Lens on my 312GW for a few weeks now and it works well - in all conditions, from full sun to unlit roads at night, and it does make a difference to the video footage.
Just one minor thing... I tend to clean this lens now and again with a micro fibre cloth, and in doing so, the cloth catches the little slots on the silver/grey locking ring, which holds the glass lens in position. Over time this appears to have loosened (unscrewed) the actual locking ring and it eventually fell out (lens n' all). Fortunately, there was no damage done, and it was just a matter of cleaning the glass lens and replacing it, together with the locking ring.
Incidentally, if the locking ring is unscrewed and the lens gets removed (accidentally or intentionally), there is a right and a wrong way to put the lens back in. If you put it in the wrong way when you come to 'tune' out any reflections by rotating the lens, nothing happens - put the lens back in the right way and it works a treat again! And don't over-tighten the locking ring either.