I've looked at Umbrel as well as Start9 and chose Start9 - so I definitely think it's better for me. Your requirements / needs may be different, so you are smart to do more research.
Start9 supports local access via https and like Umbrel has remote access via TOR. It is possible to do custom networking to get your Start9 visible remotely w/out TOR, but it is not trivial, and it isn't supported by the Start9 team. The next major release is planned to have additional networking abilities to make it easier to access remotely w/out TOR.
My experience is that Start9 is easier for folks to install and manage, but if you are willing to do more work, Umbrel currently has more services. Start9 has automated backups and service monitoring, and a GUI that I like. It does have some limitations - it only supports one hard drive (it can be very large, but only one is supported). It wasn't part of my decision process, but I did find that after buying Start9 - the customer support was amazing. I haven't worked w/Umbrel support so I can't comment there.
Start9 also offers packages with prebuilt hardware and their StartOS already preloaded -as close to plug and play as you can get. Their pricing was better than I could buy the underlying hardware for, so I was happy to buy through them. I think Umbrel also offers a hardware preloaded version, so don't get hung up on hardware specs. Both allow you to just download the software and install on your own hardware.
Start9 did compare themselves vs. Umbrel - that's worth reading too: #[2]
#start9 #umbrel #homeserver