I have one.. and it does work. It didn't appear weather resistant enough to me for my application. So I bought the GE wireless doorbell(s). They have a great RF range and can be bought in ether battery or plug-in and you can mix and match. Although there are a couple different non-matching versions (a 16 codes and 32 codes..
I think).
I bought a standard unit that hides away upstairs.. and a strobe unit [no joke] that I use in
the theater. The units allow for up to seven different and separate "
rings". This is a great feature because I have buttons at three doors, and each door has its own sound.
The great thing about the battery powered unit (batteries last about a year here) is we can take it to the deck in summer and still hear the front door even if we're doing yardwork.
I also was able to hack the receiver/ringer unit. I connected the "bell" to a PowerFlash Module.. and run a doorbell camera macro. If the TV is on.. and the doorbell rings I get an 8 second view of who is there. The computer also emails me an image of who was there. The idea was originally to see if a package was delivered while I was at work.
I love X10... but this is one application where I think the store-bought-stuff has advanages.