Yes, preferred. 50Mb is fine for the two of us and the number of devices we have. We don't even come close to saturating it.
I would gladly post you a screenshot, but for some reason I can not connect to the modem's web page now. I was looking at it last night at 192.168.100.1 and all the power levels were somewhere in the 45-50 range.
I did notice an error about no ranging response received in the log, but I don't remember the exact wording.
I seem to remember there was something screwy with this particular modem about the subnet or mask that you had to change to be able to connect. Does that ring any bells?