Thanks all for the replies.

I went with Start9, partly because the OS looked lower overhead and partly because the company appears to philosophically aligned with me and seems more bitcoin focused than personal home server. That said, here is what I learned:

1. It is non-trivial to use bitcoind and electrs without TOR on start9. Requires a bunch of under the hood linux stuff to enable. I actually haven't enabled it yet but it appears to be doable.
2. Start9 team seems to monitor their forums closely. I got a reply to a help post about this topic in just a few minutes. That is a big plus.
3. The start9 iso doesn't quite run on my minipc correctly. The kiosk mode doesn't work. That said, Tails linux doesn't run on that particular mini-pc either. Seems to be a video issue of some sort, but since Start9 can be installed without a keyboard and monitor, it still works. Seems pretty stable so far. Synced bitcoin and electrs in about 48 hours without a hicup. As long as I never need to hook up a monitor it is ok.
4. Seems that both products use Docker containers, however Umbrel itself runs in a container and then runs docker containers inside that. I think that in the long run, Start9 appears to have more flexibility once I learn to work with it. But the learning curve is steep.

However, I think I still might switch to umbrel. The TOR focused nature of start9 is a concern. I'm not sure i want Tor running all the time. I live in the US and Bitcoin is pretty mainstream and nobody would blink an eye at a running bitcoin node. But I think that TOR is associated with much less savory activities and I am leery that running TOR 24/7 might have my ISP suspicious.

The initial sync of the blockchain is pretty slow and uses a lot of data, so that is about the only thing keeping me from trying out Umbel for the moment.