Look at the Holosun units, they're affordable, get good reviews, and they make the Sig Romeos. They make one with a 50,000 hr. battery life.
These are the best values for sure............have several of the Sig Romeo 5's & at the price you can get them for, they just cannot be beat. Maybe not military grade but they work for most civilian use.
If you want significantly better then go to Eotech or Meprolight RDS at 4-5x the price.
MM
