Aero's gunsights are high in quality and very immersive.
But they are not necessarily optimum in actual usefulness, and some sights are wrongly portrayed in size.
Also, the effect he uses for luminosity tends to add a slight color to the gunsight which gets in the way of clear vision.
It's been some time since I've done sights, but there are some testbed Revi gunsights I've created myself - I use these for my German planes.
Larger in size, and a bit better visibility IMO.