I've used the 1000 in TCRx2 and TABR. It's major flaw is it's weak waterproofing of the SD slot, which I "fixed" by filling it with silicone grease and taping over the SD slot. I would never recommend the 810 but I've not used the 820 so don't know how it compares with the 1000.
The 1000 seems okay but isn’t the 820 just plain terrible?