Just had a quick play around with it. Looks great overall. The steam icon seems to fit in nicer with the others.
Just a couple of issues.
1) (I think this is a known issue): With the old system tray: I have had a long standing issue where the icons in the system tray would go missing if i turned off my screen then turned it back on. This seems to be related to UI scaling (I use 200%) and using a 4K monitor.
With the new system tray the icons get corrupted and un-usuable. I suspect it's the same issue just manifesting itself a bit differently.
Note: only the system tray icons are affected. the other things like the clock/power button/Raven button all work fine.
Note: Using a Vega 64 and the current kernel.
2) Kinda related to 1. if i remove the system tray in Budgie desktop setting then i re add it, 2 of every icon in the system tray appears. I'm not sure if that is a new issue though.
The only way to get everything back to normal is to log back out and back in or restart the system.
Also just an observation: The steam icon used in the system tray is not the same one used by the icon theme in Solus (the blue Steam icon). I don't know if that is the intended behavior or not so just thought i would mention it. Personally i think the update looks nicer.