Me and my kids have:
4 pair of Diamondback binocs. Average about 5 years old.
2 Diamondback rifle scopes.
1 Diamondback spotting scope.
Only issue has been that we've lost a couple objective lens covers (my personal Vortek pet peeve right there!!).
But we did have a Nikon rifle scope fog up this year.
Wish their warrantee was like Vortek's.
I'm sure my Vortek's don't compare to glass in higher price ranges, but within their price range, they work for me.