I would consider an external recorder if there would be a better visible signal from the HDMI port. Could be the SDI signal better than the HDMI one? So far I think the difference is not major compared to in camera recording.
The digital video signal should be identical. The difference is that sdi carries timecode, it has 24PsF, and it transmits record start/stop flags, and the connector and cabling are more robust and locking.
SDI is much more suitable for recording than HDMI is.
I just finished a week of shooting a run and gun style production using the AF101 and an Atmos Ninja
There were times during the shoot when i thought why the AF101 I could have used a easier rig (canon XF305 etc) but you just dont get the look ...and reviewing the footage each night made me smile.
Anyhow my Ninja had a conventional hard drive, on a tripod with rapid moves there were no issues, only when hand held occasionally skippy the bush kangaroo would show and I'd loose footage on the ninja (the AF101 was also in record mode as a back up). I'm sure these issues would disappear with SSD.
HDMI connector issues - the cable supplied from the hire company was problematic it kept popping out of the AF all the time, I swapped this over on day two with a standard cheap HDMI cable i carry as a spare and the issue disappeared completely.
But its in the edit thats when i really noticed the difference, you really can push the image around quite a bit more.
Even when the Samuari appears i'd still consider the Ninja, its a very nice piece of kit and considering as I'd just hired mine and went out shooting the next day I had very few problems.
I agree, I use the hdmi out of my Nano to monitor on the Zacuto. The HDMI always pops out during a run and gun situation. I finally put some gaffers on the finder and cable.