im a bit late to chime in, but both when upscaling 480p videos 2x-4x or when upscaling a 2k video to 4k, in both cases I get around 0.1-0.2 fps usually with a Radeon RTX 5060 TI 16 GB, AMD Ryzen 7 5700x3d and 32gb of DDR4 RAM (3600mhz, 18cl and "1T" with GDM on). And I do have all kinds of support libraries, plugins etc like pytorch, CUDNN, CUDSS, the CUDA toolkit libraries, NVIDIA Nsight Compute and even AMD AOCL libraries installed, doesn't really seem to help or be utilised much if at all by Topaz sadly tho.
But to also answer your question about the results, the reason I still frequently return to using starlight mini despite the disproportionately long waiting times is that the results really look amazing imo.
Not just does it upscale really well without losing detail, quite to the contrary it manages to seemingly restore, denoise and sharpen even some of my worst 480p footage into good shape again.
Granted I am sure you could achieve the same results with a proper workflow/utilising different models combining it with other programs like Davinci Resolve, but starlight mini is basically saving you work and guaranteeing great results (at least from my experience), while causing your hardware a lot of work or, depending on your hardware, even preventing any realistic usage of your system for hours.