I've had an Aetec on a 300 Ultra Mag for three deer seasons and it still holds its zero. The scope is bright and clear.

Just for kicks I mounted a Simmons 2x32 ProDiamond on my FN FAL today. Its chambered in 308 NATO. Took five shots to get zeroed, then proceeded to run another 195 rounds through her as long as she was out. Still zeroed.