Mine came in yesterday. I originally ran it directly connected to a 43" 4k TV. I am using a Raspberry Pi 4 with 4GB RAM. I found it to be very sluggish with the info crawl at the bottom of the screen, and the mouse and keyboard were as well. A reboot improved this to some extent. I updated to the newest version of the software, don't think that made much difference. I am connected via ethernet.
Then, I tried connecting across the LAN from another ethernet connected PC and it ran as smooth as can be. This got me thinking (dangerous in and of itself) and I wound up reconfiguring to run the Pi headless. The 43" TV is now the secondary monitor on one of the PC's, and I'm opening a web browser connection to the Helioclock on it, then pressing F11 to run full screen. Works like a champ and eliminates the need for having an extra keyboard and mouse kicking around the desktop.
If you have a spare Pi or PC kicking around doing nothing, this is absolutely worth the short $$. Very impressive, great interface, and thus far great support. I've received almost immediate replies when asking the few questions I had.