As winter approaches, I have had my first encounters with heavy rain. I understand from comments on this forum that the 830 has the barometer ports located behind the USB cover. Hoped this would resolve the issues I've had over a decade with Edge devices getting the barometer sensor holes plugged with water and then not recording elevation data properly. Only the 1030 has seemed immune to this. Resorted to covering devices with plastic bags and rubber bands in the past to prevent issues. Seemed like 830 position would resolve this. Unfortunately NOT!
100 mile gravel race a few weeks ago turned to pouring rain about 5 miles in. I had both 1030 mounted (on the out front mount) and 830 (on the stem). The pictures below show what happened once the rain plugged it up. I stopped at one point and put the plastic baggy on the 830 (after locking screen), but it made no difference. At the end of the ride it only had 6000' climbing for an event that had 10,000' climbing. Meanwhile 1030 had no problems at all and recorded good data all the way to the end.
Here's the 830 at a certain point on a climb
At the same moment in time, here is the 1030 below (my eyes and legs definitely agreed with the 1030)
Later on here is another example of 830:
Here is the 1030 at the same point
I will say I am quite disappointed in the 830. My friend riding with me also had an 830. His flaked out even worse than mine and only got around 5000' climbing. When he Strava elevation corrected it, total climbing went to 10,300'. He also put a plastic bag on and it made no difference. Because there are no visible holes, the trick of previous Edge devices from the 305 onwards of blowing in the holes to clear out the water is not possible, thus bad data is recorded until things dry out.
So for whatever reason, it seems that the 830 is the worst for barometric readings. Not sure why the 1030 is so good.
Even a week later, the elevation on the 830 was really whacky.
I started a ride in a different location hundreds of miles away. When turning on both devices, they came up with radically different elevation. I adjusted them both to the correct elevation and started riding. By 6.5 miles, the 1030 showed my elevation as 3600'. The 830 meanwhile had jumped back up and showed me at 4360'. No idea what was going on, but after many days, the 830 started agreeing with the 1030 both on total climbing and also elevation. When things are dry they are almost exactly synchronized.
And below is 1030 elevation at the same point - both are pretty close in Total Ascent though, which is odd.