So, while there certainly is more than graphics, that clearly seems to have been a focus. I've said the same since we started getting teases of what was going into it, that it's all amazing. I love the new HD zombies. I think the new POI's with the new assets are simply amazing.
Playing the game in A19 is smoother, feels more immersive, music better, fighting better. Exploration is richer, more engaging.
At the same time, there are some new cool stuff. Some new weapons, auto shotty, desert vulture, sniper, steel club etc.
However, I've also raised the similar that while I love Alpha 19, it's also more like a "better" Alpha 18, but it lacks the additional new content that would have really set it aside as a great version. It plays essentially like A18 does, and while that's not necessarily bad, it's also not necessarily good enough either. If you want to keep people continually engaged (as opposed to play once and then put on the shelf) there needs to be continual content drops that make people expand their gameplay accordingly, as opposed to "I did it pretty much like before, it was smoother, but essentially the same as before."
But all is not lost! What I would have recommended, would be to:
1) Put in the junk drone in a patch sooner rather than later. I don't care if it's perfect. Heck, stun baton was broken all of A19, Junk Sledge was broken. New content is always good.
2) It was highlighted on the streams that melee bandits were essentially there. So put them into a POI. Put them into a wandering horde. Ranged not ready? fine. Put in melee bandits. Let us play with them, experience them, and while they might not work as they will later on, who cares? New content wins.
3) It was also mentioned rafts/zombie fish/shark whatever was "almost" there. so put it in. Spend the couple of weeks to get it in, and let players see how "some" of it works now we even have swimming zombies.
More content would make people be happy we had a graphics update AND excited to try new things with new systems, such as simple bandits, simple rafts/water hazard.
Even more so, as 2+3 was mentioned as "almost there" and needing some "glue" to finish off. Superglue it, duct tape it, and get it in for patch 19.2
/Ved