Bests & Worsts Reviews from Amazon

First of all, I've been using Amazon for several years and bought countless number of products and I've been always happy. This is the first time I'm writing a review, because I'd like to warn other users before making a mistake I did. I've been using Garmin Edge 500 for almost 2 years and I simply love it. It's small, accurate and never failed me. One of the reasons I wanted to upgrade was to have a bigger screen (I was excited about 10 fields per screen 510 offers). Another and the most important reason was support for GLONASS system (500 on a few occasions wasn't too accurate in canyons or forests) and I was hoping to have a better GPS signal. The fact that 810 doesn't come with GLONASS was the reason I chose 510 (otherwise I'd go with 810). This still puzzles me as to why Garmin decided not to include GLONASS in 810. As soon as the package arrived, I eagerly unpacked it and realized that the device was larger than I thought. I connected it to my computer to transfer my old profile and the first thing I noticed was that it had less free space on the device. 500 has about 50MB while 510 has only 22MB and some of that is taken by the system files leaving around 17MB. Garmin, really?! How much would it cost to add more flash memory? 50 cents? Just to give you some idea - a typical longer ride with 1 second recording takes about 500Kb-1MB. It's convenient to keep a few rides on the device before uploading to the computer. When I researched this issue I found out that some users were unable to update software, because the updated would take 9MB space and it wasn't enough... Note taken, but it was still manageable. I had set up the device, created two bike profiles and went for a test ride, which happened to be my commute next morning. And this is when the sky fell. The screen is totally unusable in the sunlight. I was like, I must have screwed up something, this cannot be. I turned on the backlight permanently at maximum setting and yet it wasn't light enough to get the same contrast as my old 500. Then I realized two issues. First of all, the new screen has less sharper font, because it has a color screen and practically the resolution is lower than 500 and secondly it uses a different technology which is more susceptible to daylight. I live in California where we have 300+ sunny days in a year and 510 simply sucks. That was a big disappointment. I tried various settings, changing angle, etc. Still not as good as my old 500. Same data field, in a 8-field screen setup, is less readable than on 500. If you actually look as to why, you will see that Garmin decided to use larger font for labels, which wasted a lot of space and left actual numbers smaller and less readable. This whole color screen is a BS. It doesn't allow any customization and simple degrades readability. For instance, I'd love to set up different colors for different power/heart zones. It'd be cool to see I'm exceeding my power threshold just by looking at different text/background color. Apparently, Garmin engineers thought it was a better idea to use color primarily for the grid lines... Like it was not enough, after my ride back home, I carefully compared elevation profiles between 510 and 500. 510 showed twice as much elevation gain on the same route and when I zoomed in, some segments had a bumpy line where I'd normally expect a flat line (50% of my commute is at sea level). Sorry Garmin, another epic failure. It's hard to understand why it would be worse than the old generation. Again, I found some users complaining about the very same reason and it didn't surprise me. I'm sending my Garmin back to Amazon thanks to the great return policy and I advice anyone who is considering buying 510 to think twice. Don't make the same mistake as I did. Garmin, please wake up.