Mbus 3 improvements are worth the extra $ - Magpul Industries MBUS 3 Front Rifle Sight

The MBUS 3 sight housings are slightly smaller and lower profile than the gen 2 while being much easier to adjust (no tool or makeshift implement is needed for the front sight, and the rear sight's small to large aperture selection is made easier with separate apertures separated by 45 degrees of rotation - no more prying apart with your fingernail - just a flip!). Durability and accuracy seem to be as good as previous versions. The front sight post is dual width while the rear sight large aperture seems to have a slightly enlarged diameter over previous versions, which gives you a better view of the outside prongs of the front sight. I was looking forward to the adjustability of the front sight, however it's the improvements to the rear sight aperture that will have me replacing all the backup iron sights on my ARs with the MBUS 3 versions.