So, the same as both the HG612 & the HG622. Eric & Paul will be glad to hear that.
I bet Eric will add it to his list of routers by the end of the day!
Performance will come down to the firmware then. e.g. I find that a straight swap-out of the HG612 for the HG622 on my line (i.e. in bridged mode as simply a modem; no WiFi, routing, PPP or anything else), results in a 25% increase in interleaving depth with a corresponding 5Mb/s reduction in attainable rates.
Not a problem ATM, but could be decisive if my attainable started to decline closer to the product max.
Off to read more detail around the threads you posted (thank you), but at first reading, some of these were provided by a member of PN staff with spares, and it seems it is probably running the 10.n firmware. (You can get the 10.2.5.2 firmware for your current TG582N from PN now, and get some of the functional benefits).
PS: Beat me to it Eric!