I have the Garmin Edge 705 and love it. Fancy the 800 but can't justify the price when my 705 is working well and Santa has other things to buy for the kids! To be fair there's probably more functions/data on it than I require but I love my gadgets and gizmos!
I use the speed sensor and cadence sensor and as it's mounted on the rear it's ideal for use during Turbo Trainer Sessions. You can also create your workout on it or on Garmin Connect and export it to the device,
If you have the money I'd personally go for a Garmin, others may say different.