The short answer is Yes.
Should you consider upgrading your Edge 705 to an Edge 800. The short answer is also Yes (subject to budget and partner approval of course).
The Edge 800 is a better product. For those upgrading from a 705, at first, it will feel like that moment when your supermarket changes the way it's laid out.
You know, you're normally in and out, know where everything is and crack your weekly shop out. The menu structure has changed on the 800, so you need to look around a bit in the menus a bit to re-familiarise yourself.
Bikeradar have done a great review of the product here, far better than I could write. I'll add some bullets below of the key observations I've made.
- The user interface is the major improvement. The touch screen is much easier to use on the bike than the previous button pushes on the 705. The colour screen is brighter and easier to see.
- The handlebar mouniting system has been improved. 705 uses a slide in system, there is a risk that the unit can fly out of the bracket (few people have reported this). The 800 uses a rotation based click in system now - much better. Rather than use cable ties to mount on your stem, the Edge 800 uses rubber bands, so it's easy to transfer between bikes.
- Calories used information is much better. The Edge 705 isn't particularly accurate. The Edge 800 uses a better algorithm and is much improved.
- The Ege 800 features the ability to look in maps in more of a 3d mode - like a Tom Tom. It took me a while to find the menu command to switch this on, however I've found that it's a much improved view of the map when riding and the user experience is much improved.
- The unit now alerts you move and prompts you to start recording. This is one of the drawbacks of the 705 I found, forgetting to press the start button meant no ride data. Good job Garmin for fixing this.
- Navigate to course. If you load a course, but start in a different place the unit gives you the option to navigate to the course - another improvement.
- The menu structure is much easier to navigate. The 705 is a bit fiddly when setting up or moving around the menus, particularly when you're moving. The Edge 800 being a pressure based screen means that - gloves on or off - you can quickly get through the menus with little fuss.
- Number of data fields has been increased to 10 from 8. If you want a full dashboard of ride data, there are an additional two customisable fields for you to add.
- You can swipe between data fields, like an i-Phone. I've found this pretty helpful to switch between screens mid ride, particularly if you want to check an upcoming ascent or your ride data, whilst following a map direction.
- The virtual rider mode is easier to use. Good for training, just flick into this screen and set an average ride speed you want to achieve and the full colour screen give you a great little animation should your progress. I never used this on the 705 as I could never figure out how to properly set it up. The Edge 800 makes it easy.
- The USB cable is much shorter than the one supplied with the Edge 705. It's nowhere near long enough and means your unit will either be on the floor or dangling from a plug. I think Garmin should put the old one back in.
- The colour scheme is either Black with blue trim or Black with white trim. Cyclists are a funny bunch and can be a bit anal about everything matching. I'd just make the unit black and be done with it (like the 705).
- There are two rubber plugs in the USB port/SD card ports which are a bit fiddly. Garmin have obviously done this to ensure no water gets in. I think it would be better with one cover which clicks into place with a waterproof seal.
Pricing and Range
Garmin Edge 800 - basic headunit RRP - £349.99. Around £315 on the web.
Garmin Edge 800 with cadence sensor and heart rate monitor around RRP - £399.99. Around £359.99 on the web.
Garmin Edge 800 Performance and Navigation Bundle - RRP £449. This includes the Heart Rate Monitor, Cadence Sensor and City Navigator Maps. Around £399.99 on the web. This I think is the best value of the lot as you get everything.