Agree, Star9 is quite superior if you need more than simply a node, electrum and dojo.
I do not feel is a good practice to mix anything with a Bitcon node that is not related, therefore, star9 is a setting I use only for self sovereign server with cloud services, but no Bitcoin, I try to remove any possible additional attack vector to the device.
Umbrel OS works without stability issues if not mixed with anything else but Node, electrum and dojo,.
I think both are awesome, but each one for a different use case.
Did you buy the star9 HW solution or install it in a server of your own?