It seems umbrel is a bit more technical.
MyNode looks like plug and play
I currently have one running on Umbrel, but I am using a VM, and it’s a bit slow to connect to. I want to get one up and running on a raspberry pi soon, just haven’t had the time.
MyNode requires manual updates if you don’t go Premium. Umbrel of ease of use and one click updates. I personally use MyNode for BTC only and Umbrel for Lightning. Comes down to personal preference. MyNode I’ve had less issues with though.