This post sums up what is new about the Garmin Edge 1040 vs 1030 Plus, so you can make up your own mind if the upgrade is useful for you.
do NOT upgrade - Garmin Edge 1040 Review
Garmin Edge 1030 Plus vs. Edge 1040: Should You Upgrade?
do NOT upgrade - Garmin Edge 1040 Review
Garmin Edge 1040 vs 1030 Plus vs 830 vs 530 Bike Computers: In
Garmin Edge 1040 Solar GPS Cycling Computer - Performance Bicycle
Garmin Edge 1030 Plus vs Garmin Edge 1030. What's the Difference
Cheap vs expensive bike computer: What are the differences
Garmin Edge 1040 vs 1030 vs 830 vs 530 GPS Bike Computers: Full
Review: Garmin Edge 1040 Solar
do NOT upgrade - Garmin Edge 1040 Review
do NOT upgrade - Garmin Edge 1040 Review