Are there any disadvantages to the solar version at all?
I live in Denmark, so solar charging really wouldn’t give much of a beenfit, but currently the solar is cheaper than the non-solar version here, so if they are otherwise identical, I might as well get it (and use it as an excuse to travel to somewhere with sun…)
No idea why they’d price the solar cheaper than the non solar… get on it! 
They probably bought some at the distributors and can’t sell them because everybody thinks like me, that they won’t need them in Denmark. 
Yes the screen is not as bright
Plus side is you get solar and with double the storage, world maps
You can find it for cheaper, there are some 20% off coupons every now and then. Check out Biketiresdirect.
To the original question, I went from the 530 to 1040 Solar and have zero regrets. It’s amazing. I wanted a bigger screen and tried the Karoo 2 but it just wasn’t up to par with features and the battery life was terrible. So I picked up the 1040 and couldn’t be happier. With the Solar, I charge it like once a month. The extra screen space is awesome and makes the data fields bigger, but I use the map screen the most so it’s nice to have a bigger map and a couple data fields. The big thing I was afraid of was the touch screen not working well but it’s been flawless.
I did order it. Got 20% through my health insurance. But ordered it through garmin and their processing time is 2-3 weeks. I did consider the hammerhead as that screen size almost seems like the sweet spot. But I figured I wouldn’t be happy with the feature set and battery life. And also I’m used to garmin eco system
I just switched from a Karoo 2 to a 1040. I’ve only done a few shakedown rides on the new gravel bike I built, but it’s been good so far.
As for the Karoo 2, it has some genuinely excellent features (navigation and routeless Climber especially), but the negatives are just too much right now. But especially the battery life. I was tinkering with some settings on the Karoo in the morning before one of my major gravel events and turned up the brightness a bit while I was double-checking the route and tinkering with some settings (from my usual 35% up to 65%) to account for some major glare around the start area, then forgot to turn it back down.
I’d never had battery issues before, but that 30% bump in brightness meant that the Karoo ran out of power about 4 miles from the finish on a 70 mile event. Everything was clearly marked and I made it back just fine, but not capturing the whole race was infuriating. I put it up on Ebay a week later and bought the 1040 when I found a good deal. Having the battery life be so short that a 30% bump in display brightness reduced it from the usual 8 to less than 4.5 hours is just not acceptable. I shouldn’t have to pay that much attention to screen brightness that it could impact a single ride under 8 hours.
The Karoo 2 irked me when I accidentally zeroed out my power meter during a ride from their control center drop down while trying to get a sensor connected again. I was also a victim of the “if two things beep at once your Karoo 2 crashes and you lose your ride” issue. >_>
