opinions on a psu

Solution
The XFX is fine. Nothing needs to be changed from the original build. It's balanced and has quality parts. The only reason to change a component out is because of personal preference.
I would recommend you sticking with that XFX TS gold PSU. The Corsair CS M is Tier 3 (like holyrage mentioned). If you want any better than that, I would recommend the EVGA Supernova 'G2' (performs better than any other Supernova psu, even the GS and G1 edition)