Hello! I skipped most of this thread, but just wanted to say I generally agree with the OP's conclusion that the class is basically "ok." It seemed really great when I first read it, but upon closer examination I agree it suffers hard from being a late bloomer - which also makes it harder to multiclass. It also makes the spellcasting progression even worse - you are clearly not meant to sling spells around the battlefield in an offensive way. The SAD thing seems cool - and if you roll for stats and get only one good stat, then it's great - but it does mean you will be quite awful at combat for at least two levels. Granted, those are supposed to go by quickly, but it's sort of crazy how much difference there is between a level 1 artificer and a level 3 one, and it made me not want to play one. I get the feeling that WotC was extremely wary of people taking a level 1 or 2 dip into this class just so they could abuse magic item creation or elixirs, so they made it awful long enough to scare those folks away. They may have also been worried about dips from artificers into other classes, which is why it takes so long to get your good stuff. And when you're writing gimpy classes because you're worried about multiclass abuse, we're getting back into 3.5's problems.
Also agree with the sentiment that an artificer is there to be a support character, which makes some of their subclasses a little weird. If you wanted to get into melee or be a blaster, you will do a lot better as other classes. Ironically the temp HP is probably the best thing about the artillerist for that reason. Also, because of the versatility, this is NOT a class for beginners. To maximize your efficiency you will need to have a strong command of all sorts of magical items and effects, keep track of pets and bonus actions, and you're making big decisions about all these things every short rest. I feel like this hurts the class, because it's absolutely built for people with specific non-D&D fantasy tropes in mind - like Ironman, or someone who just wants to have a flamethrower. Beginners could have had a great time with the archetype, but no beginner should play this class.
Overall, I'd put them in the same sort of category as a trickery cleric or a forge cleric. But it's hard to recommend being an artificer over one of those. Or a bard. I agree with others in this thread that an artificer would shine best in a game with less combat, lots of exploration, and low magic. They would also work well in a game with only 2 or 3 characters, as they can fill many non-combat roles. And these are great features! Because there are games that need a role like that.
But for your more "standard" D&D campaign: just play a bard.
Sidebar: I think if a class really starts to shine around level 9 you can call that a "late bloomer" because I remember reading somewhere that most games end by 12 or 13 or so. I know I've literally never played or been in a campaign with a level 14 D&D character in my entire life. So I also tend to think of level 12 as your "capstone" and give little credit to abilities past that point.
