Swap Aetherize for Cyclonic Rift
  Costs more, but higher impact than Aetherize, better in early game.
  Usable earlier, in case really need to spend it
  Better against early game Heroic all ins, worse against hexproof
  Can hit enemy PWs and Spheres

Making room for 1x Fated Retribution in the main
  Very averse to cutting a counterspell
  2x Az, 1x Flare, 2x Last Breath has been a very solid removal package
  Most likely thinking to cut Elixir
      Original thinking was going up to 28 lands slowed me down
      Elixir a hedge, early life gain.
      But I'm thinking with 6x PWs, enough game winning threats.
      Aetherling might be better anyway in the main
     

Azorius Keyrune to replace 28th land?

Debtor's Pulpit in the sideboard

I want access to more card draw in long, drawn out games.  Div has seemed too slow for non-control matchups, though.  A 4th Rev, miser Opportunity, perhaps just card draw in the sideboard?
 
Swap Flare for Selesnya Charm, consider swapping Elixir for one as well

I like the thought of trading Aetherize for either Disperse or Cyclonic.