USB G may be a bottleneck for some depending on the Internet connection
available. Despite this most will still get a decent connection. The USB N
adapters will be supported soon enough...
You can install a kernel from Jason's repository (jxself.org/linux-libre) and
firmware manually and its not too difficult (http://jxself.org/ath9k-htc/).
You should also be able to install the 3.5 kernel from the main Trisquel
repository and download the firmware manually as well.
* I think taking the 3.11 linux-libre kernel from Jason's repository is
probably the best idea though. I don't think I was ever too happy with the
3.5 release. There are various bugs which can cause problems with some (many)
USB devices (on some computers).