The latest trend for pistol red dots is using different window sizes to match specific use cases. There are options with large windows for quick target acquisition, small windows for concealed carry, ...
Right now, Palmetto State Armory is running a big sale on the Vortex SPARC Solar 2 MOA red dot optic; you can get it shipped to your door for just $89.99. Compare that to a sticker price of $349.99 ...