Now that the finalized version is out, it looks like there are only minor changes, so it is, unfortunately, still a dud for me. From a formatting perspective, seems odd to have the laboratory feature lumped in at the end of the spell list. The construct capstone feature is okay, but it's generally a worse companion than the O5e battle smith just gets and doesn't have to use up infusions for AND you don't get it until level 20, so that's kind of meh. I do like that they swapped modifications to using up infusions instead of spell inventions, but otherwise almost none of my questions/concerns were addressed, so... yeah. Really bummed about this one, was hoping for something better than O5e and I kinda feel like it's generally worse.
here are the changes i could find:
-a spell invention now requires its material components in addition to the gold cost (nerf, but fair)
-clarification: you only need to spend the gold and material components if the invention is a new one (good, but not really a change)
-you can draw a spell invention in the same action you cast it, and also stow any other spell inventions you were holding as part of that same action (buff)
-you gain more infusions faster (you have only 2 for exactly one level), and gain a 7th at level 17 (buff)
-marvel of innovation now gives you advantage on prestige checks in any region your invention has been sold in (buff, and now level 13 isn't a dead level, so very good)
-hotfixer now lets you use your reaction to basically negate a fizzle die (this seems to be a clarification - the original says "when casting a spell with one of your spell inventions to destroy it" - so, good, but overall not really a change)
-the capstone has been changed entirely - which is good, the lab had absolutely no right being a capstone - but it has the same problem as the lab (and a lot of the artificer features that weren't changed) in that it sort of just comes at you full force with no build up. additionally, it takes a spell invention and TWO INFUSION SLOTS to keep running, and you can't even make multiple of them. this is a capstone, why the hell is there an arbitrary limit on the number i can make? i'm competing with WISH (well, actually, i've been competing with wish since level 17, but you know what i mean) and GUARANTEED DIVINE INTERVENTION for gods' sake. i'd only be able to make 3 anyway. also it only has a +2 proficiency bonus and not very good ability scores as well as health that's lower then its creator (12d8+36, where an artificer of this level will probably have 20d8+40 or higher health), which further makes me question why i can only make one. that health especially hurts when you realize it takes 30 damage instead of its spell burning out. and, finally, this feels like it's stepping on the stitcher's shoes a bit, just sort of giving you a free minion (overall, better then the lab, still not very good).
-...ok, wait, you...still get the lab at level 20, it's just after the spell list. i'm very confused. is this why you can only make one automaton?
-mousetrap adds a d6 instead of a d4 when determining how much supply is captured (buff)
-alchemical prodigy replaces clearcut camping, and it seems to be the only way outside of finding schematics or studying magic items to get new schematics, but you're limited to common or uncommon potions and can only take it once (this...exists?)
-reengineering nature replaces water purifier, and actually seems like a pretty decent field discovery since you can just get spell components
-wide burst is now standard for all the bombardier's grenades (which, honestly, good, i don't know why it ever wasn't)
-arcane payload is a new option for a bombardier grenade and gives the bombardier something to dump infusion slots into - rattling a target and dealing a bunch of extra d12s sounds pretty funny, not entirely sure it's worth an infusion slot but i guess we'll see (also, i'll ask here - do the grenades deal any additional effects from their arming options to targets that fail the dexterity save? i'd assume not, but again i figure it should be clarified)
-modifications for the engineer and stitcher now use infusion slots instead of spell inventions (kind of a nerf, surprisingly - you only have a maximum of 7 infusions, but you have a maximum of 16 spell inventions thanks to subclass spells...although, you can eventually create any infusion you're using to replicate a schematic, so in the long run this could provide a lot more flexibility and avoids the odd problem of the bombardier being the best artificer caster. i guess we'll see what happens)
-the engineer's huge vehicle grants the passengers half cover as well
so, basically, a lot of balancing tweaks and a couple clarifications, and giving you a second capstone but then putting the original at the end of the spell list, and neither of the capstones are really that great at all. you still have no guarantee of additional schematics (unless you take alchemical prodigy, but the schematics you can get with that are very limited in scope and you can only take it once), the scaling of some of the abilities is still unnecessarily rapid, and you still get more spell inventions from your subclass then your actual class. so...i guess that's where we're at.