I would say ~8. It depends on how you think of the 1-10 rating system. I say 8-8.5 if 10 is the absolute best computer that will fit in a regular desktop case and 1 is a mainstream computer from 10 years ago.
If you were to think of it in terms of what percentage of PCs in regular use that build would be better than, then I would think that that percentage would be in the very high 90s.
I've never thought about what percentage of PCs in regular use today are enthusiast gaming rigs, but I would like to know. If you have built this rig you can always run benchmarks to get a better idea. If you haven't, you could look at Passmark scores for systems with that CPU&GPU and find a system that closely resembles that one.