It's hard to beat the customer support either side. You being closer to Arizona than you are to AI could have an impact but neither one should require much in the way of service unless you over heat one. AI tends to be faster on the service side than Cactus but both try hard to get them done quickly. DA can't be faulted anywhere in the way of service. The 3W would provide a bit more torque but how much do you really need? The next issue comes up where DA has a 150 but 3w has a 150 and 157, with the 157 available with twin spark.

If it was me I would be looking at the 157TS, but money hits the table here. In a 40% plane the second ignition is an insignificant weight factor and assures that the plane lands under power when an ignition unit decides it wants to take the rest of the day off.

Personally I believe you are down to an end price ready to run to make the determination. Both are excellent choices.