Hi. I currently use the Omnipod Dash and am very happy with it. For a short period I used the Medtronic 640 but changed to the Omnipod as I found the set changes difficult due arthritis in my hands.
I suppose much depends on whether you want a tubed or tubeless pump.
If you go onto YouTube you would be able see videos showing set and changes. This might give you some ideas of what is involved with each pump. You can get a sample pod from Omnipod if you want to see what they would be like to wear.
I can’t comment on the OmniPod Dadh but I’m currently using the Medtronic 780. It’s been great, so far! Few little teething issues but largely, I feel, as I was new to pump therapy. It’s quite bulky so finding the best place to “hide” it has been a bit of trial and error. Everything is pretty easy, though!