Brainadict, just picture, you are repairing a TV or audio amp and want to know the capacitance and D or ESR of the 10.000 uF electrolitic filter cap at 100 Hz. Do you think a VNA will be helpfull ? Or a 1000 uF with a ESR of 0.05 Ohm in a switcher at 15 kHz, that is Z=(0.05-j0,0106) Not the area a vna is very good. It gives impressive values with lots of digits but the accuracy in that area is very bad unless you use special measure techniques. Probably you will manage to measure this with a vna, and I can do to, but people who need advise about a LCR meter will not become happy with a VNA. And one mistake with a bit of charge and you kill your vna.
Besides that, I do not see my self power up the laptop, vna, calibrate it, solder a cap to the fixture and make a sweep. If you have it always powered on, why not, but it is like dragging a caravan behind a ferrari, or drivinf a defender over a circuit.... In that time I have measured 10 caps with my GR1608 and then I'm sure the value is correct. Even my 1620 is quicker, but like Conrad, I love my bridges but for quick results during building or repairing I use a IET DE-5000. For radiowork, filters, component research I use the vna.
(@conrad, the GR-1608 is also one of my favorites in use (but the 1620 is my pride), but a beautifull GR-1603A and an original manual is now on it journey to Holland)
For me and a lot of experienced users calibration is no voodoo, but for many users it is. And your results will be as good as the calibration.
You developed the Xtal option so you can measure Xtals ? I do not have that option, not in my 2.6 and my 3 is production number 1, Toms proto, as far as I remember it has a tcxo or something like that, not the normal Xtal but I never really looked ) both are able to measure Xtals with the Xtal tool in Toms software. If you install the Xtal, do you need extra software ? But my 2.6 performs slighty better as my 3. My 3 will not go over 1300, the 2.6 I have used it over 1500 but that was more indication then measurement)