It is next to impossible to get Vodafone to tell you your connection userid and password which you need to use your own router. - Despite what their sales staff might tell you.
One solution to the Wifi problem is to switch of Wifi on the router and then use separate Wifi devices.
There are some happy customers, so it is not all bad news! Their price is very attractive, so if you can live with the above, they are certainly worth considering. IMHO
Vodafone have their own forums so you can learn more from them.