I've built the first unit with the ECS ECOC-2522-10.000-3-F-C. It made it to mode 3 overnight, which is much faster than "first light" for an OH300. At not quite 24 hours in, the average phase error reported by the diagnostic log output is hovering in the low single digits, and the DAC is dancing in a corridor of around 3 units width, perhaps aging upwards fairly slowly.

Interestingly enough, the reference voltage output of this unit was measured at around 2.8V rather than 3.3. That said, the current DAC setting is 0x27A13, which when you scale it is around 1.733 volts. So the reference voltage is lower than expected, but the actual center point is just over the actual Vcc/2 midpoint.

ADEV testing for this variant is pending. I want to wear it in a few days and then run it against my Thunderbolt. In principle, the ADEV claimed by ECS is around what the Thunderbolt itself claims, so I may not really be able to work out the actual quality of this one myself. Not sure where I'll go from there. I rather suspect sending it out to be tested by a proper lab would be more than I could afford.

If it turns out that this unit is equal to the TB, then I will probably retire my TB and start actually eating my own proverbial dog food.