This is a great guitar out of the box. The frets are very nice. No need to touch them up. The P90 sounds good. Potentiometers are fine. The tuners felt a bit mushy - not in the action but in the tactile feel of the plastic button, but it hardened(?) after a short time. The only adjustment I made was to lower the bridge to my preferred string height. I was able to get a very low buzz-free action.
I wound up installing three-on-a-side tuners, an ABM bridge (and later a Gibson wraparound bridge) and a Gibson P90. None of these are necessary, but I cannot help but to tinker. If you are thinking of upgrading anything the greatest benefit I experienced was the bridge. I prefer the aluminum bridge to the brass, but your preference may differ. Again, it is not necessary to alter anything - it is a very good guitar out of the box. I switched from stock bridge, to ABM brass bridge, back to stock, to Gibson aluminum (?) bridge. The ABM bridge adds brilliance. Switching back to stock it felt like the guitar became slightly dynamically muted (a sound I did not mind at all before the first bridge swap). The Gibson bridge restored the lively feel with much the same tonality of the original bridge.
Highly recommend this guitar. Great product at a very affordable price.