[HTC One S] el_smurfo:
Sorry, not near a computer with adb right now, but I'll try a bit later in the weekend. There are some posts in the old 10.1 thread. Someone was trying to track down the exact commit, but disappeared without a conclusion. It was definitely before the 3.4 kernel introduction, and some folks over there have stated the 5/21 unofficial was the last build without the drops.

EDIT: Looks like CatLog has a radio option. Hopefully this helps, but there's definitely an error flagged in there when switching bands

08-16 16:29:26.389 D/PHONE (1315): [ServiceState] setDataRadioTechnology=11

08-16 16:29:26.389 D/use-Rlog/RLOG-QC-QMI(237): qmi_qmux_if_rx_msg converted service_id = 3

08-16 16:29:26.389 D/use-Rlog/RLOG-QC-QMI(237): QCT_DEBUG: posting msg to service handler[0xb6a01675] client[1] conn_id[0]

08-16 16:29:26.389 D/use-Rlog/RLOG-QC-QMI(237): API Flag .............. 1, Message ID ............... 77

08-16 16:29:26.389 D/use-Rlog/RLOG-QC-QMI(237): qmi_client ed: sending 47 bytes on fd = 18

08-16 16:29:26.389 D/GsmSST (1315): [GsmSST] handlPollStateResultMessage: GsmSST setDataRegState=0 regState=1 dataRadioTechnology=11

08-16 16:29:26.389 D/use-Rlog/RLOG-QC-QMI(237): qmi_client ed: Received 54 bytes on fd = 18

08-16 16:29:26.389 D/use-Rlog/RLOG-QC-QMI(237): qmi_qmux_if_rx_msg service_id = 33

08-16 16:29:26.389 D/use-Rlog/RLOG-QC-QMI(237): qmi_qmux_if_rx_msg converted service_id = 229

08-16 16:29:26.389 D/use-Rlog/RLOG-QC-QMI(237): QCT_DEBUG: posting msg to service handler[0xb6a01675] client[1] conn_id[0]

08-16 16:29:26.389 D/use-Rlog/RLOG-QC-QMI(237): API Flag .............. 1, Message ID ............... 207

08-16 16:29:26.389 D/RILJ (1315): [1072]< VOICE_REGISTRATION_STATE {1, 003d, 05168869, 3, null, null, null, null, null, null, 1, null, null, 0, 0}

08-16 16:29:26.389 D/RILJ (1315): [1073]< QUERY_NETWORK_SELECTION_MODE {0}

08-16 16:29:26.389 D/PHONE (1315): [ServiceState] setVoiceRegState=0

08-16 16:29:26.389 E/PHONE (1315): [ServiceState] setState deprecated use setVoiceRegState()

08-16 16:29:26.389 D/GsmSST (1315): [GsmSST] Poll ServiceState done: oldSS=[0 0 home T-Mobile T-Mobile 310260 UMTS HSPA CSS not supported -1 -1 RoamInd=-1 DefRoamInd=-1 EmergOnly=false] newSS=[0 0 home T-Mobile T-Mobile 310260 UMTS HSPA CSS not supported -1 -1 RoamInd=-1 DefRoamInd=-1 EmergOnly=false] oldMaxDataCalls=20 mNewMaxDataCalls=20 oldReasonDataDenied=-1 mNewReasonDataDenied=-1

08-16 16:29:26.389 D/PHONE (1315): [ServiceState] setNullState=1

08-16 16:29:26.389 D/PHONE (1315): [ServiceState] setNullState=1

08-16 16:29:26.389 D/GsmSST (1315): [GsmSST] getCellLocation(): X good mCellLoc=[61,85362793,0]

08-16 16:29:30.013 D/use-Rlog/RLOG-QC-QMI(237): qmi_client ed: Received 64 bytes on fd = 18

08-16 16:29:30.013 D/use-Rlog/RLOG-QC-QMI(237): qmi_qmux_if_rx_msg service_id = 3

08-16 16:29:30.013 D/use-Rlog/RLOG-QC-QMI(237): qmi_qmux_if_rx_msg converted service_id = 3

08-16 16:29:30.013 D/use-Rlog/RLOG-QC-QMI(237): QCT_DEBUG: posting msg to service handler[0xb6a01675] client[1] conn_id[0]

08-16 16:29:30.013 D/use-Rlog/RLOG-QC-QMI(237): qmi_service.c RX indication for conn=0, srvc=3

08-16 16:29:30.013 D/use-Rlog/RLOG-QC-QMI(237): Processing indication: Message ID= 81, Service ID = 3

08-16 16:29:30.013 D/use-Rlog/RLOG-QC-QMI(237): Client 10300 gets indication callback