I have Comcast Xfinity and routinely get 21mbps down/3.5mbps up, and can typically get those speeds on my E4GT as well (at least when I'm on the same floor as my router). I have had some issues of the wifi connection 'dying', where I notice that I have no connection although the wifi icon is still showing in the task bar. A simple off/on of the wifi fixes it everytime, and only takes about 5-10 seconds or so, but still it is a bit annoying that it consistently happens.
Of course, I don't know for sure if this is related or due to an issue with the E4GT or with my network, but it doesn't happen with my laptops or my Galaxy Tab 10.1 so I'm inclined to think that the issue lies with the E4GT.