Of course, the other consideration (giving that it is wireless) is that leaving it on, and unmonitored - not that it is, much, when at home, is that it's an opening for people in the area to leach your internet bandwidth, if they have managed to break in)
As for being on to download firmware? Give me a break - I have had a telstra delivered CG3100D2 for three years, and there are known bugs, still not resolved, and there has been one firmware update in that time (which didn't fix the problems...)