Thanks everyone, this thread was very helpful. Newegg via ebay had a great deal and my Vega 64 is on the way. I'm going to start with undervolting and likely reach for a Morpheus II after I put the reference cooler through its paces.
You'll never sustain peak speeds on Vega with a 100% load. It's always going to be short by 8-20Mhz until AMD fixes their GPU boost which I doubt will happen on Vega. Running my Vega 64 LC at 34C and at 300w while the GPU core is set to 1750Mhz but only runs between 1700-1730Mhz.
Only time I can run it at 1750Mhz is when I overclock to 1770Mhz. Less demanding games end up overboosting to 1800Mhz+ and crashing. Vega's GPU boost is garbage and overclocking is irritating. At least with nVidia cards I could run GPU-Z to find the max boost of that clock speed and than the frequency drops when the temperature is higher than 65C. Vega shouldn't be allowed to boost over the target GPU frequency but it does.
Mh no you do not have a golden chip, but indeed a good one. You're using 1100 mv for both of your last p-stes. Why? Because unless you registry edit power play tables you can't go lower than the 3rd last p-state voltage.
If you do something like this and don't play with uncapped framerate (which is a stupid way to play in my opinion, capped framerate feels better than unlocked even with freesync, Radeon Chill and RTSS are your friends). You will have a very power efficient card that will also boost higher when you really need it.
The P6 and P7 states are the only ones you can edit, that's why the voltages of P6 and P7 are lower than 1100mV.
I can run 1730MHz at 1V on core, haven't seen anyy other cards that can. I didn't use Radeon Chill, no point with custom loop. But did use FreeSync.
Unfortunately I need to RMA the 64, cuz it's giving me issues in-game.