I have the duos. At current prices, I'd probably just get the uno. You trade a little accuracy for the price, but the reality is that while I do use the power data, both for training and pacing, I rarely look at the pedal dynamics other than to say, "huh - interesting." My left leg seems to be a little stronger than my right, but from all I've read, it's not enough to worry about. The uno will still provide consistent numbers, and as long as it is all you are using consistency is probably the most important thing.
I will also say I love the ability to switch easily between bikes. Just don't be like me and remember mid-ride that when you moved them from the gravel bike with 170mm cranks to the road bike with 172.5, you failed to reset the crank length on the head unit....