Red Dots - is the solar panel just a gimmick?

I’m looking into an RDS for a Glock 19 and am seeing great reviews and deals on Holosuns. Love the shake-awake, durability, and RMR cut compatibility.My main question is this - is the solar panel just a gimmick or does it actually improve battery life? The difference between the 407c and the 407a3 is just the solar panel and ~$50. via /r/CCW https://ift.tt/2SYuyUx