The 0806 is definitely preferable, as well as what CYL wrote it gives better quality video even though it uses the same sensor.
Most of the issues have been sorted, there are a few left which need a firmware update but they are all for features the 0805 doesn't have anyway.
There seem to be a few dregs of the second batch still around, I suggest you ensure that you get one from the new 3rd batch that has just been released and which has had a few minor modifications to ensure it is constructed correctly and avoid the trapped cable issue.
In recent weeks, most of the reported issues have been due to fake microSD cards being used, not issues with the cameras, or the sequential use of the two memory cards working differently to expected.
You should be aware that some of us have a vibrating rattling filter showed in the video below and talked about in a later page of the link below. Apparently that is going to be fixed in a yet to be released version (3.5 mod?) but they said the same thing about the GPS issue being fixed in the batch 2 mod . Several have reported the GPS issue in batch 2 which is why batch 3 mod is coming out. I have batch 2 and have not experience the GPS issue.
It has been suggested the rattling filter can be fixed by tape. I am unable to fix with tape which makes the filter useless for me.
The other issues I'm experiencing should be able to be fixed in firmware. Let's hope the update will be coming soon. The mini 0807 thread in the mimi 0807 forum talked a lot about the still existing issues with the 0806.