Marty:
No one has responded so:
We used AC and DC for hot wire feeding back at an aerospace company I used to work for. This process was used to weld small to large diameter sheet steel (primarily rocket exhaust cones) of inconel or titanium, depending on the application. There was also cold feeders used at this facility for aluminum, but these were rarely used.
We had procedures for both AC and DC, I did not notice any difference. The AC was utilized to minimize any arc blow (as you already know) problems, but I never experienced any myself. I tried both programs with the AC and DC and could not tell the difference myself. I did not enjoy this mechanized station and prefered to work on the bench. Adjustment of the torch guides during operation was required now and then, but that was it, I found it boring.
The only thing I do remember about hot wire GTAW was keeping the shielding consistent about the heated wire assembly and the trailing cups. Something seemed to leak whenever it came time to qualify, but it ran fine during production. The shielding usually consisted of lots of tin foil and home-made trailing cups. If the shielding was compromised on the wire feeder for titanium, then the part was considered a very expensive paper weight.
Maybe it was the "watched pot never boils" effect.