I've been a pretty loyal user of the Connor Winfield OH300, but it's always a good idea to look for other options.

And, sure enough, there is another option that looks compelling: the ECS ECOC-2522-10.000-3-F-C.

The form factor is remarkably similar. The only real difference is on the OH300 the bottom center pin is NC and on the 2522 it's a Vref pin. Using that would save us the need to add a separate regulator for the DAC reference voltage. There are two more pins on the top edge of the OH300, but they're NC.

Electrically, they're quite similar, but the 2522's pullability is ±700 ppb instead of ±400 ppb, and the lifetime aging spec is ±500 ppb instead of ±300 ppb. But on the flip side, the low frequency phase noise is 5 dB lower through 100 Hz on the 2522. They don't list a short term Allan deviation spec (the OH300 claims 1E-11 @ 𝜏 1s, but in my testing I actually see more like 8E-12). Additionally, the OH300 has a "dead band" for the control voltage of the outer 0.3V. The spec for the 2522 is rail-to-rail.

The pullability specs for both suggest that with the 2522 the 18 bit tuning steps would be a bit coarser. What that winds up meaning when the rubber hits the road is, however, an open question.

Lastly, the 2522 is $40 more (Q:1). Whether it's worth $40 more...? We'll have to build one to find out.