Do I want to upgrade my modems - VMG1312-B10A devices ?
(To 1312-B10A-17-jumbo-tel-x6-stats-cmd.bin )
I'd be inclined to say - why fool with a running piece? With lightning issues and engineers coming I would keep as many variables as possible the same.
That said, once you have stable lines they are some benefits from the new stats server. Everything under /data updates on access rather than having to perform a /getdata or relying on /data/varStats.
But I would not change the adsl_phy modem code unless you want to test, stick to 1312-B10A-17-jumbo-tel-stats-cmd.bin, or even one with less. No problems making a 1312-B10A-17-jumbo-stats.bin if it suits.