I agree with most of the what the op says...
The replay for A17 will be very boring and exactly the same. Something totally different than previous versions. As others have said, I always got a kick from starting over. With A17, I actually dread it. Basically it comes down to kill approx 249 Zombies to get to level 20.
Me and the wifey enjoyed the base building and crafting aspect more than the zombie clearing. I will say though that I do like the higher difficulty of the zombies and the improved AI. The fact that they can dig down to an underground base only livens things up and makes it more exciting. Better have a good escape plan!
I am not a fan at all of the new stamina/ health systems. I spent the majority of the first 15 days at 25 health just because I couldn't find first aid kits or bandages. I don't really like having to eat foods to keep my max stamina high or having to use first aids to keep my max health high. Just doesn't feel like a good system.
Personally not a big fan of the skill system. It pretty much dictates your progression and will take away from the replay value due to the fact that all replays will be pretty much the same. I am more in favor of gaining xp in whatever you are doing, kill with rifles = Weapon xp, farming and mining = tool xp, etc. This system of just killing zombies non stop to level up gets boring very quickly.
The quest system so far is looking outstanding! Kudos on this one! This will definitely add a very cool element to the game. I've only done a few fetch quests, but so far I do like it alot.
Not really sure about the dungeon system yet as I was never much of a raider/ looter ever since most sleepers were ferals for me. Just part of the game I didn't enjoy. I did go in 1 dungeon so far just because I knew it would be a good source of zombie killing/ XP. From what I saw, it looked good and did have quite a fun aspect to it.
Haven't experienced the mod system yet, but from what I see, it looks absolutely beautiful! Been hearing on some servers that we cant craft them yet.
Love arrows sticking and being retrievable, that is awesome!
To sum it up, it really feels like the customization of each persons play through has been removed or severely gimped. Every play session will be pretty much the same and get boring pretty quick. I was a 60% base builder, 20% looter, 20% zombie slayer where my wifey was 100% crafter. Now she cant be a crafter unless she kills a ton of zombies.
I am over 3000 hours and have been playing since A7(?) This is definitely one of my absolute favorite games and I have tried all the survival games. Hopefully things will get tweaked to improve the gameplay on this version.