I agree with the majority on this thread, bike GPS units are far better at following a planned route composed at leisure on a computer, they are less impressive if you actually try and plan a route using one. To plan a route on a computer my personal favourite is
RWGPS, I like that you can toggle between driving, cycling and walking; using driving to make sure I stay on roads and toggle to walking if I want to walk over a footbridge for example. Plotting a route on a computer is all part of the build up for me, I'm in my mid fifties and plotting a route reminds me that back in the day I would have on OS map in the bathroom that I would read 'on the toilet' merrily planning my next ride
I still use my
Garmin 810 that I bought in 2013 and is still actually available from
Madison the UK distributor, note you can use the unit to
plan a route (click for video) although it is a bit of a faff, that said I have used it on the rare occasion and been pleased with results, but I much prefer pre planning where possible. Of the current Garmin range if I were buying now I would choose the
Edge 830, in many ways a touch screen version of the
Edge 530 that uses buttons instead; I find the former far more intuitive to use than the 530 and well worth the extra £90.00 at retail as far as I'm concerned. The 830 is so impressive I'd actually choose it over their flagship model the
Edge 1030. All the current units have a listed battery life of 20 hours, where as my 810 has 17. I'd treat all of those as optimistic, that said I have never run out of battery but when on tour I do carry a
power bank in my
'handlebar bag' as back up just incase, if needed the usb lead easily reaches the 810 located on my stem. There are quite a few GPS units from other brands,
Wahoo,
Satmap,
Bryton and
Lezyne to name just a few, all have there pros and cons and note some have more a focus on training data than they do navigation
Although I plan courses using
RWGPS, I do import that route into
Garmin Connect so that I have a back up on my phone if needed, I can also use the same app on my phone to plan a route from 'point to point' as well as a 'circular route' over a specified distance which I have found of some use when on a center based holiday when I do not have my computer with me or pre planned routes already loaded onto the unit.
I do find a GPS incredibly useful, most of the time I love it, but there has and I dare say will be the in the future the odd occasion where it will send me
around the bend when it should've
navigated me around it but didn't! Like any GPS I would recommend not relying on the navigation too much, like many who use GPS systems in their car you will find the odd occasion where the system will not do what is expected and you need to over ride the presented information with a large dollop of common sense!