I'm with the Moose. Part of the reason I bought a TX was to have the TomTom with it, but when I read the damning reviews of the TomTom (especially its tech support) on various public sales sites I said no thanks.
I got a Nuvi 300, and I love it. And Garmin have *great* tech support. When I asked them if they did maps for Japan, they said no, but various people had coded ones that i could try, and suggested one - with the caveat that they took no responsibility for it.
The maps for Ireland are currently so-so outside the big cities, but NavTeq's satellite mapping is going to be included on the Version 9 software, due out late this year or early next.
And they're about to have a Mac platform at the same time, so Mac users will be able to download maps and install them on their Garmin GPS devices then.