When I opened my email on some forgotten time, I got
an invitation to try a shiny new host with sdf
features but built with a different os.

The hostname is beastie.sdf.org

It has different ssh public key than tty.sdf.org and I
can't get password authentication to work.

Fortunately, public key authentication is working.
Just a little addition to ~/.ssh/config to add
beastie.sdf.org with my username and I was able to
login into beastie.

Well, what is different from tty.sdf.org?
First: the os.
beastie runs OpenBSD instead of NetBSD
Second: programs installed.
Fewer programs are installed, but the list is growing
as needed. Missing programs can be requested via
bboard.
Third: ssh host key
A new host key prompt should be triggered during first
ssh login and will be saved for next ssh access.

Ok. My experience with beastie has been so awesome.
Here is a bonus: neofetch from beastie as of
Tue Feb  8 10:13:05 UTC 2022

mydeardiary@beastie
-------------------
OS: OpenBSD 7.0 amd64
Host: Supermicro X7DBT
Uptime: 97 days, 16 hours, 29 mins
Packages: 189 (pkg_info)
Shell: mksh R59 2020/10/31
Terminal: /dev/ttypc
CPU: Intel Xeon X5460 (8/8, SMT off) @ 3.159GHz
Memory: 272MiB / 16367MiB