We've got them and we've unboxed them. See a quick video review comparison.
Garmin announces the Edge 540 & 840 series of cycling computers
Garmin Edge 1040 Solar Review
Garmin Edge 540 vs. Edge 840 (Solar): Which One to Buy?
Ride Review: The Garmin Edge 540 and 840 Solar!
Garmin Edge 840 Cycling GPS In-Depth Review
Garmin Edge 840 Cycling GPS In-Depth Review
New Garmin Edge 540 and Edge 840 with solar charging launched
Garmin Edge 540 Solar Bike Computer
New in: Garmin EDGE® 540, 840 Solar and EDGE® 540