I replaced my solar garmin instinct with the Forerunner 965. For the most part, the battery life didn't change. I'm still going through the settings and tweaking everything the way I like it. Soooo many settings... I've done multiple 70+ mile rides with this watch over 8+hours of active use and a ride like that typically takes the battery down 30% or so for me. Otherwise I'm liking it. I don't think it has any other real advantages over my last watch as it's still the same Garmin software running.
I chose to buy the Garmin Edge Explorer 2 because I wanted a bike computer that can display maps for navigation and that integrates with a Garmin Varia rearview radar, but that doesn't need to include the advanced training features that the more expensive Garmin units do (as I personally don't care about that).
So, for those purposes, this bike computer works well enough.
I wouldn't say it's perfect, though. The user experience is a little clunky. It kind of reminds me of cheap Android smartphones from 15 years ago, which is a little disappointing considering the Edge Explore 2's price.
The Edge 840 is a really good GPS computer. I purchased this after my Wahoo Roam started being unreliable. The detail and capabilities of the Edge are superior to the Wahoo. I do most of my riding solo and the LiveTrack on the Edge provides much more detail than the tracking on the Wahoo.
The one negative I can think of is that the setup and menus on the Edge and the Garmin Connect app are WAY to complex. It seems like any sort of configuration change on the Edge is buried three layers down in the system menu.
This bike computer was an upgrade for me from a Garmin Edge 130 Plus. The technology isn't the latest, i.e., no touch screen, no solar power. However, the upgrade has provided many advantages over the 130 Plus.
Here's what I like: 1) More data and fields per screen. E.g., the 530 records fluid and calorie consumption, derailleur and gear status of Di2, and up to 10 data fields per screen. 2) More available screens. 3) Longer battery life by a wide margin. After 3-hour ride in 45F weather with screen brightness at 60%, battery is between 75 - 85%. 4) Faster processing and syncing. Syncing routes from RideWithGPS now takes seconds, not minutes. 5) I like the summary screen and data that are available after a ride.
Here's what I don't like: 1) It takes some time to learn the function of the 6 control buttons. They're very different from the 130 Plus. 2) While the 530 offers color maps that can be browsed, the navigation process is very antiquated. Moving about on the maps is very slow.
The 4-star value rating comes from the retail price remaining around $300, which I believe is high compared to other computers and newer technology that's available. Overall, I like the computer, feel it's a good improvement over the 130 Plus, and would recommend it to anyone who wants solid function and capabilities at a moderate price.
