Thanks, I'm on a Huawei cab (hence the HG612) - so just to confirm, you think on a Huawei cab the HG633 is a good option?
I would say so, it will increase your SNR margin so you will see a slightly better sync than the HG612 in most cases (unless at full sync where the line will become more stable as no more speed possible).
Thanks again, I'll see what sync speed I get to, the main reason I wanted the router upstairs was location, but I'm sure if it's a decent modem I can make a plan to leave it close to the telephone socket.