This build has evolved a lot throughout the ever-changing meta of Standard. The deck's early build have performed well at a PTQ, getting 11th place. Half the deck is you basic Abzan midrange build with Caryatids, Coursers, Rhinos, Elspeth and having key spells like HD, Abzan Charm, and Bile Blight. The other half is Constellation featuring Underworld Coinsmith, Eidolon of Blossoms, and Doomwake Giant. One of the main players of this deck is Underworld Coinsmith. Having one or two the field will give you constant lifegain with each enchantment you play, and it will stick around due to the low intimidation factor. The lifegain helps cancel out the rather painful land base and small scale attacks to you. Its activated ability is very strong mid/late game, draining your opponent an average of 2-4 damage a turn and taking damage from the ability will not be a big problem because of the lifegain from Courser and Coinsmith combined. The activated ability is also incredibly strong against control, eliminating top builds like UB and Sultai control. Once they figure out how much of a threat Coinsmith is, they will go out of their way waste their removal and counter spells on it, and you will have the opportunity to get bigger, more important spells on the field like Doomwake, any walker, or Hornet Queen.
"Differing" Design Choices:
Thoughtseize: I ran Thoughtseize as a 4 or 3 of in early builds, but it does not do as much for this deck as other Abzan builds. Turn 1 it was better to get a dual land out to go into a Caryatid or Coinsmith than rather get a pain land out Turn 1 and waste time by putting a dual land out. The mana base is extremely important for this deck and that is why is took Thoughtseize out all. (One can also go on about how Thoughtseize lost some playable value in Standard because of the current meta. Nevertheless, Thoughtseize is still a very powerful card in many Standard builds.)
Sylvan Caryatid as a 3 of: Sylvan Caryatid gives enough value just by having 1 or 2 on the battlefield. 4 Caryatids seems to overkill since all this build needs is just 1 or 2 plus Courser is a 4 of, which means constant land drops. The curve was kind of clogged mid-game since I'd rather be drawing more important things like a Rhino or a Doomwake. That is why Sylvan Caryatid is a 3 of. (Sorry if it was droning on.)
The Land Base: The land base chosen is painful, but helps much more than it hurts. Out of hundreds of games, the board state has been mana-deprived in a color about 5-7 times. The land base is quicker and more painful than other Abzan builds, but it pays off because of the lifegain present.
The Sideboard
Anafenza/Fleecemanes: Against control or even slower midrange builds, one can turn the deck into a more aggressive deck by siding the Anafenzas and Fleecemanes in.
Pharika, God of Affliction: Great to control the board a little bit and snag some extra constellation triggers. Use the snake tokens as a combat trick or just stack them EOD to keep pinging the opponent.
Good matchups: Sultai Control, Abzan Midrange, RDW Aggro, Mono Black builds, UW Heroic.
Neutral: UB Control, Jeskai Tokens, various Mardu builds.
Bad: G/GW Devotion