I'm one of the Dronepan developers.
I'd just throw in that we didn't want to remove the gimbal yaw in Dronepan - but that a change in the SDK is still causing issues that we're still trying to fix. The plan is definitely to add it back - but it has to work first. It's being worked on - but - most of us are on our summer holidays at the moment - so it may be a little slow.
As to slow - yes - it is. We made a decision to only move on the next shot when the drone itself reports that the previous shot is saved since there were a lot of people getting missing shots. We send the "take a shot" command and the SDK says "OK - I'll send that" - but the next info you get is by watching the status changes - taking shot/shot taken/shot saved. Sometimes the command is not received by the drone - and you have to wait to see if it needs sending again. I'd love to speed it up - but - if you get a missed shot then the entire pano is wasted

We'll keep looking at it (we're evaluating - is it enough to wait for shot taken rather than shot saved for example).
And that drift issue - oh man - we got a response from the SDK developers that a firmware update had removed drift protection on yaw - and we're still trying to find out if/when it'll get added back.
I love the gear - I love the fact that it provides an SDK - but it does feel from time to time that you're aiming at a moving target.
Anyhow - I'm still on my holidays - but there's loads more help/info/discussion on the
dronepan facebook group - you can also ping me on here - but - the group would nearly always get a faster answer