Very old, an 802.11b specification (max 11mbit).
Looking around, some say the 5.3 firmware can improve things (if it's not already at that level) but still leaves it with the discredited WEP as the only security option.
http://support.netgear.com/app/answers/detail/a_id/625
Many forums say that the V3 firmware can be loaded, to enable WPA, but other reports question the reliability when updated this way (tendency to freeze, require reset).
It's a "cable/DSL" router, ethernet in, so pretty much any router of this type can be placed after the modem, and the setup will usually sort out by the auto/wizard options.
There are some cheap routers that are quite adequate