I have been working on an asymmetric Dominion map named Kostal Kombat.
There are 4 Bases (The map layout allows 4 bases without the gameplay suffering).
Each base has a trait zone around it that gives a different effect, Alpha gives Speed boost, Bravo gives Damage boost, Charlie gives Overshields, and Delta gives an enhanced radar.
The map is highly asymmetric with a lot of verticality, and will support up to 8v8 matches (5v5 or 6v6 is recommended).
As you can see from the screenshots, the map has several routes to each base, as well as plenty of opportunities for risk/reward.
The map is still in the works, but I will soon be posting a download link.