question about the wifi connector

ok i have a few questions about the Nintendo wifi stick thing that plugs into your usb ports.

1, will it work if the computer is upstairs (2nd level) and the wii is downstairs (1st level)

2, if so would the connection be strong?

3, is it worth it?

4, and finally are other wireless routers a better choice instead of the Nintendo thing?

i appreciate the help. 

my ds will not connect to it if there is the slightest obstacle between it and the usb router

also, it will not connect to nintendo wifi connection at all if you even have a zone-alarm firewall installed, regardless of whether its on... you have to completely uninstall zone alarm.

i strongly recommend a normal wireless router, its faster and better range... i connect my wii to a proper router but unfortunately i have no control of the router and the DSs router connectivity options for security encryption are "WEP" or "nothing" so only my wii can connect to the psk-tkip network in my house and i had to get the usb doomaflatchy...

my ds will not connect to it if there is the slightest obstacle between it and the usb routerCRAZIE_GUY

The Wii has a far greater range, for me anyway.  My room(Where my Wii is) is like about 25ft away from my computer and there are 2 walls in between. I cant connect my DS, but my Wii connects great.