I think Nate is correct. Options do matter. Not all of them, but tracking options can be significant. At a minimum:
L2C
L5
GLONASS L3
Galileo
I especially think that if you are running matched (or similar) Base / Rover pairs you want to track Galileo today. There is a significant number of Galileo SV's available now, with a couple more that may come online real-soon-now and 4 to follow later this year. There are usually two to five extra Galileo birds in view here (SLC UT) which can make a big difference in deep canyons with trees. Adding 6 more Galileo SV's will be a big deal next year.
Of course, if you are working in a network that only provides corrections for GPS and GLONASS, then Galileo and BDU won't help much. If you are working out in the desert, GPS only is probably just fine. The advantage is under canopy and/or in canyons.
If I were purchasing a GNSS receiver today, I would want it to track GAL and BDU without having to pay extra later.
I posted some examples earlier [ GNSS Centric ] .
