I have also received the last week an iMac 2019 5K with the same configuration. Very happy with it so far.
My configuration is almost the same:
27‑inch iMac
i9 3.6GHz
8GB RAM (I've upgraded it to 40gb, Timetec Hynix 16GBx2)
Radeon Pro Vega 48
512GB SSD
Magic Mouse 2 (I also use another optic mouse that I like).
I added a 1TB Samsung T5 and I am very satisfied with the machine. Excellent performance and dead silent.
My question is: at what room temperature are you obtaining these benchmark results with your new i9 iMac Vega 48? Because I have these weeks a room temperature in excess of 32° C (yes, it is like working inside a sauna). Ambient temperature sensor 45° C.
I am obtaining slightly less values in the benchmarks with the same exact machine configuration. 33400 multicore geekbench 4, 143000 metal (no warming up of GPU before the tests). I think that this could be due to the relatively high room temperatures in my studio these days (i.e. 42° C to 44° C outside during various days and no A/C yet in my room, also tropical nights +32° C outside at 2:00 am). I think that the climate change is slightly affecting my iMac performance
.
But, in general, the machine is running smoothly and silent which is a very good thing. It is a very good iMac 2019 configuration, in my experience.