The 800 is last years 810. Improvements in contrast and light output, and a better lens. A new memeber here posted a few weeks ago after seeing the 800 and 810 in the same room, and reported that the difference was marginal.
Spend some time in the master 810 / tw700 thread. There are a few comparisons between the 810 and the Panasonic, including those of Joe Black who is the prominent poster there, and switched from the AX100 to the 810.
Jonathan