Hiya!
As at least one other person has said, I'm not keen on your list of choices.
"Maybe, some other thing" would be mine.
I have no problem with 'quality levels' of items. In fact, in my own homebrew system based on the old Darkurthe Legends RPG, I created a "QL" ("QualityLevel") scheme. I call it my "CPAGMEL" (See-pag-mel); Crap, Poor, Average, Good, Master, Equisite, Legendary.
Each of these levels has a %'age associated with it in regards to benefits, costs, and availability (as well as the minimum Skill Level required to even have a chance of creating one). Anyway, the "benefits" can cover anything in particular to the item at hand. It is a fairly loose system, allowing the player and GM to tailor a particular item towards some goal. A "Good" quality saddle could be described as "Extra padding gives the rider a more comfortable ride, letting them extend their normal riding day by around 5%", or it could be described as "This saddle has smooth-beveled ridges into key locations as well as excellent stirrups, giving the rider a 5% better chance of remaining seated under situations that might otherwise cause a rider to fall", etc. And yes, this means a Exquisite QL Dagger could have +4 to attack...but as I said, 5's range of numbers doesn't allow for this level of detail (I guess a +4 may be the equivalent of about, oh, +1 or +2 in "D&D" terms), whereas in my RPG ("Fantasy Elements" is what I called it), that bonus is nice to have but not unbalancing for 'low level' (no levels in the game, btw), but gives 'high level' users a much better edge. In 5e, it's a pretty flat curve from 1st to 20th level.
Anyway, with regards to 5e, because it has such a limited range of adjustments (+1 vs +3 is a pretty big adjustment, for example), I'd have "Masterwork" items be equivalent to "specialized" items; that is, they aren't "better at everything" for that item, they are "better at one aspect" for that thing...lighter, stronger, faster, etc. I DO NOT think that weapons and armor should have "pluses" from Masterwork items...not even with just one 'part' (e.g., +1 to hit but not damage). They should be desirable from a ROLE-PLAYING side of things and not a COMBAT side of things. You want bonuses in combat? Magic weapons or skill...simply tossing GP's and getting almost the same thing cheapens the magic, imho.
^_^
Paul L. Ming