Roll Out Gutter extension

I Recently purchased two roll out gutter extensions from rainguard. They were pretty cheap ($16 a pop) so I liked that, but will they work? Well, this is mid February in New England so when I first put them on a week ago it was cold but sunny for 3 days, then it proceeded to snow for the next two. The upshot is, I don't even know if they work yet (I'll update as soon as I get a good chance to test them), but here's a few thoughts right away -

• They are easy to fit, just take them out of the plastic box they come in, stick the supplied sealing tape around the downspout, then slip the open end over the downspout, and secure. They supply a black plastic tie, but in both cases, this broke, so I used an elastic band instead.
  
  
• They look kind of goofy sticking to the end of my gutter downspout. Not sure I like the look of them especially with the elastic band I used.
  
  
• I didn't think about the snow! For them to roll out, they would need to be free of any impediments - and the snow covering them is bound to make things difficult, when the snow melts of when rain comes. Will the water collect at the bottom and cause a problem? Watch this space...