Ok, odd observation based on my own ignorance.
It looks as if the issue I am experiencing is related to the handoff from LTE.
The reason I say odd is because I guess I mis-understand what exactly WCDMA is within the AT&T network. I was under the impression that it is used for 3G data but I forced my handset to WCDMA only and it identifies if is on "4G" (not LTE). Does AT&T use the WCDMA modulation mode for 4G as well?
Am I operating from a false premise in that WCDMA = 3G?
With that, the data for streaming was more stable/reliable when I forced the handset to WCDMA only or selected WCDMA preferred, leading me to believe the issue is isolated to LTE service (or the lack thereof). My crude observations also suggest that LTE is VERY sensitive to shifts in signal level and becomes unstable quickly.