I have never had a box of 100 Mustad 36890 hooks that had zero defective hooks. However, with Daichii hooks (which is the only hook brand I tie on), you are lucky if you find a single hook defect in 1,000 hooks of the same size and style. To me, quality hooks do not have defective hooks in virtually every box of 100 hooks. I've seen hook eyes not closed, hoks bent, hooks broken at the bend, eye loops not tight against the shank, eye loop retruns bent away from the shank, points that were malformed, shanks that had kinks in them, and shanks that had forging nicks in them in boxes of Mustad hooks. These are quality problems.
The lack of a nice tapered hook return on them is a pain to deal with when tying because the hook return is not very long making it tough to tie a nice small unobtrusive head. The hook return also makes it difficult to tie the head of the fly back from the hook eye a 1/16" or so to facilitate the use of improved turle knots that seat on the eye wire and not the fly's head. The Daichii hooks have beautifully formed tapered loop eyes, even in #1/0 and #2/0 heavy wire standard salmon irons. The Daichii return wire is not only tapered right into the shank, they are much longer and it is easy to form the fly's head with the 1/16" gap behind the hook eye.
The 36890 hook temper has a lot to be desired as well. The temper of the 36890 is on the soft side and I've seen 36890 hooks open up the bend when fighting fish. The hook point on them also doesn't hold up very well when you hang a rock because of the temper either, which neccesitates the need to inspect the hook point any time you hang up no matter how little to be sure the point wasn't bent requiring resharpening. In contrast, Daichii tempering is excellent. I've never seen a Daichii hook bend totally straigthened. Yes, I've seen #5 or #7 Alec Jackson Spey Hooks (which are made by Daichii) bend to the left or right; but I've not seen them straighten the bend. And the Alec Jackson Spey hook in #5 and #7 is of much smaller diameter wire than the 36890 in #10.
The finish on the 36890 is also not very consistent. There will be runs or spots on the hook were too much finish was put on the hook during manufacturing on quite a few hooks in a box of 100. This is also a hook defect because if you tie a tinsel or floss body these defects will show through. Again I do not find these probelms with the Daichii's that I exclusively tie on.
If a person is looking only at price of the hook, Mustad has a place; however, there are other choices among the lower priced hooks that have better quality than Mustad. Dai Riki for instance is much better quality than Mustad standard hooks for about the same price.
Many of the things that I find unacceptable in Mustad hooks are of no consequence to many others. As a result, Mustad sells a lot of fly tying hooks in the U.S. They are an OK hook; but they are not a high quality hook. Sort of like the difference between a Chevy Corsica and a Mercedes Benze. Me? I'll take the Mercedes and pass up the Chevy when it comes to hooks.