I have not had my ECM recall done yet, but I have an appointment to have it done in almost 2 weeks. I anticipate that my results will be about the same as you have noticed so far. I will inform you of any new information a few weeks after having the recall done as to give enough time to collect good data.
I had mine done last weekend with an oil change and then I drove 350 miles returning home from my weekend commute. I thought things ran a bit smoother though it could have been the lack of snow, the oil change, the increase in tire pressure or just the placebo effect. I was just glad that it didn't reset my lifetime mileage reading.
I had my recall repair done in January, and about the only change I've noticed is that my check engine light actually turns off sometimes now. Other than that I've noticed absolutely no differences in performance.