IMO, AW's are only useful to people later in the tech tree. If you aren't at least in Dwarves, you probably don't really need to worry about them, because under no circumstances should you be 'tech locked'. In fact, I would go so far as to say that until you hit Dwarves, none of your AW's are worth the space in your town because the returns are simply anemic to anything you can conventionally build.
Let us take a practical look at some comparisons that I personally experienced. As with any example of the sort, YMMV due to your personal playstyle preferences.
* Golden Abyss. This is a 3x3 building that provides a percentage of your active population. However, my level 15 buildings provided around 440 pop at a 3x3 whereas at around 11k population used the level 2 GA only provided around 300. I'd have to increase my population used by over fifty percent for it to hit an equal mark, that's not something that is likely to happen before Dwarves. And Dwarven Residences exacerbate the problem, being available immediately after the initial portal and turn into a 2x5 building which stacks more easily and has more pop. In all honesty, this is one I could probably have put off until Faeries. Perhaps even Orcs.
* Great Bell Spire/Crystal Lighthouse. This is a HUGE building that looks awesome and amazing. Free goods? Well... not free, this building is HUGE. It is a 6 x 4 building, and it produces your three boosted goods. However, it produces your boosted goods based on how many visits you can manage. So, let's say you are at the beginning of Dwarves and have 100 provinces for the chest. Roughly a third of the spaces you have unlocked are cities you can visit, so that's around 33 visits, plus let's add in 25 for a max-sized FS. Assuming no overlap, that's 58 visits each producing 30 goods each for a total of 1,740 goods total, or 580 of each type of good. Per day. I don't know about you, but for me personally, this was less than three hours worth of production. So again, it isn't really worth it at the beginning of Dwarves, and I really should have waited until Faeries or even Orcs to get this building. Having said that, I likely wouldn't have been able to clear out the footprint for this building at that point, so I guess there's that.
* Endless Excavation. Basically competes with Workshops, so let us see how well it compares. EE is a 5 x 4 and produces a percentage of your MH supplies. Assuming you have a 15 MH when you hit Dwarves, that means it will be producing 13,200 supply per 24h. However, a level 15 Workshop is a 3x4 that produces 828/h. So right off the bat, workshops will tend to produce more for less space. But then you take into consideration Workshops get a culture boost but the EE doesn't, and you start really skewing it in favor of just getting another workshop. Again, something I should probably have let slide until Faeries or Orcs or at a minimum waiting for Dwarven MH upgrades.
Mind you, it isn't that these are bad buildings. In the end-game, they can be extremely relevant, but due to their scaling stats, they are all but worthless until you are deep into guest races. Which is when you'll likely get your first experience with tech blockage.
tl;dr version: don't rush 'em. Wait until you have a reason to build them before building them. You'll likely be dealing with Faeries or possibly orcs before they become relevant.