Umbrel definitely has more apps in their store, and if your plan is to use it as a home server, then Umbrel may be the way to go. That said, the lack of ability to add external drives is definitely limiting for that use-case. I am not sure about Start9's support for additional external drives, though, since I don't use it as a home server.
I don't use the same device for my Bitcoin and Lightning node as for my home server. Part of the reason is definitely how much room the chain data takes up, but also it is better to have your node dedicated to only Bitcoin services, and put unrelated things on a different device. The more things you install outside of Bitcoin services, the more attack vectors you introduce.
Start9 is my preference for a Bitcoin node for a couple reasons. First, because it is open source. Second, because the new update they are working on will add much more control over how you connect to your node remotely, and which can be controlled on a per-service basis. That way, I can expose just one service to clear-net, if I want, and everything else only accessible through Tor, or through a VPN. Third, because I like their built-in backup service.