I was about to upgrade to the 810 until I read some of the reviews.
Sondra Swarbrick, Amazon
17 May 2014
Summary: I bought a Garmin 800 about a year ago for the same price as the 810 goes for now. I have had zero problems with it. The battery lasts seemingly forever. It has never frozen. It has never shut off for any reason, unless I turn it off. And it loads great to their website AND I can create courses on their website and download them to my 800! If I get lost, I just tap "HOME" on one of the screens and it takes me home. I've had to do that twice so far.
Summary: The Garmin 810 is full of bugs and idiosyncrasies related to mapping and route guidance, which is why most people want to buy it. I’ve been able to get it to do route guidance properly in only 1 or 2 of the last 5-6 rides. If you call up a Course to ride and hit the Ride button too early while in the parking lot, turn by turn route guidance doesn’t work (other riders have similar problems with other Garmin models).
Summary: The biggest draw for me in purchasing this particular unit was the ability to plan and upload courses of 50+ miles that could include many turns and back roads to avoid traffic and prevent me having to stop periodically to make sure I was taking the right turn. While this unit performs well with respect to speed, cadence, heart rate, etc. it does not navigate well and is very buggy.
Freezes, and Garmin hasn't fixed for over 8 months
9 October 2013
Summary: I've had the device for only a week. I used it for 4 rides. It froze on my 4th ride when I was following a course, requiring a hard reboot. I lost 46 miles of my 102 mile ride (miles 33-79) because of this. I track my rides and losing this data on my first century (100-mile organized ride event) really upsets me. If Garmin fixes this, the unit is great. But unfortunately I browsed around and this is a known common issue that Garmin hasn't addressed in over 8 months.
Summary: Selling firm and shipping was great - very quick, well packed. Now the unit: It's still buggy (even with firmware 2.7). I've had this unit shutdown on its own for no reason mid ride (battery was almost 100%), twice since I've owned it (and that's two weeks). Contacting Garmin support gets you the modern-day script following troubleshooting, none of which actually addresses the issue. Garmin forums also contain many other users with similar problems.
problem is hardware and can't be fixed with software upgrades
12 August 2013
Summary: I bought and returned this unit. I have an edge 500 and was looking to step up. The screen on the 810 is hard to read due to poor resolution, contrast and illumination. Frankly Garmin should be ashamed of themselves for putting out such an inferior product, especially given the premium pricing and the fact that better screens are available. (BTW - the 510 is also bad and both the 810 and 510 have worse screens than the older 500.
Summary: If Garmin's target audience is the cyclist who rides a few dozen miles per summer and thinks that spending big money on flashy parts makes them a better rider, then this product is perfect. If Garmin thinks this device will suit the needs of a serious cyclist, they have a lot of redesign to do. Starting with the positives first, the 810 does do some things well.
Summary: I have had many Garmin GPS units for car, boat and bicycle. Generally, I am a Garmin fan. Hands down, though, this is the worst of the lot. From the outset the unit has had problems serious enough to make me nostalgic for my Garmin 800. When using a map card, the unit would freeze up and shut down. Only way to use it again was a forced reset. The unit would then take 5 - 10 minutes to reacquire satellites before it would work again.
Summary: I bought the Garmin 810 about 3 weeks ago, and I had high expectations. Its not a cheap product but i wanted something that would do mapping as well as heart rate, and would work for both a mountain bike and a road bike. I didn't mind spending a bit of money if the product was good. However it is a disappointing product.