As far as I know the only difference is that the 890 allows RF. Thus, it can transmit through walls. There have been a lot of problem with this device and the european version (895) was even removed from their web site. However, I have heard many positive remarks lately and it is back on the web site so I have ordered it now.

Regarding their web setup, it seems a bit limiting and annoying. You can try it out on their web site. However, it seems to be good enough for me :-D Maybe I change my mind when I get mine ;)