I used it on Norwegian (shorthaul), it is a free service that they offer for everyone, so I guess that quite a few people tried to use it.

I connected on my kindle (fire, if that makes any difference), and although it did work (I had no problems whatsoever connecting, and I had a constant connection), I didn't find it that fast (I am guessing that it was from the Wifi and not the Kindle, I don't use the Kindle much for wifi), it was fine for checking/writing emails or instant messages, but I wouldn't have used it for much more.

For a free service I must say that it is good.