On the outside they are identical... just different colors:
On the backside, there are 6 TORX screws. After removing them, the touchscreen sensor panel can be removed (just be careful with the flex cable). This procedure is identical in both units.
There are 2 TORX screws holding the lcd panel.
After removing the LCD screen, the main board can be extracted.. little pressure and the connector releases
Both touchscreen sensors are identical
both LCD screens are identical
Same batteries. Batteries are hold in place with some soft glue.. below them there the little speaker.
main boards: edge 800 on the left, edge 810 on the right
backside of the main boards after removing the RF shield
Same barometer (MS5607-02BA01)
same GPS LNA (Infineon BGM781N11)
same GPS frontend (ST STA5620C)
The 800 has a Samsung MCP memory K5 that combines in side the same IC a MobileDDR RAM running at 166MHz, 256Megabits en 16 wide bus and a NAND Flash of 1Gigabit in an 8 wide bus (K521F57ACA-B060)
El 810 has a similar spec´d RAM+FLASH but its Memocom brand instead of samsung
Both units use an ARM cpu manufactured by ST for Garmin.. By looking at the P/N it seems that the 810 has a different (better?) cpu
Voltage regulation is identical in both units
Both units share the same SD/MMC level converter (WM406L)
Both units use the same fuel gauge ic (Maxim 17040)
I couldnt id the rest of the IC.. if somebody recognizes any of them, please let me know
800 uses NordicSemi nRF24AP2 for ANT+ (8 channels)
810 uses Texas Intruments CC2567 which integrates ANT and BT inside same silicon.Next 2 pics shows 810 ANT/BT:
As we can see, the 800 and 810 are very similar devices. They basically added BT, perhaps a faster cpu (not confirmed) and they deployed a new firmware
I dont recommend upgrading from 800 to 810 at this time... 810 software is still buggy, Livetrack does not work well (probably because IOS/Android apps are buggy) and Turn by Turn navigation will work sometimes for part of a route but most of the times it will crash the unit without any warning.