I was quite surprised to see no other reviews for this device as it has been around for quite a while, I have had mine for over two years.
Like many Archos products it makes a good video recorder and perfectly adequate music player. Also, I have often used the simple text editor with a standard, small USB keyboard attached, to prepare letters when my laptop would have been too much to carry with me.
It mostly lets itself down with the add-on functions: the wireless has very limited range, while I can connect to my access point from across the building with my laptop and Nokia N800, I need to be in the same room for the PMA430 to work. For network connectivity, ethernet is far more reliable, I use a Dynamode USB to ethernet adaptor. The Opera web browser is let down by the limited screen resolution, but it does work at a push. I have had trouble getting the e-mail program to work with some accounts. Desktop synchronisation requires a quite out of date version of QTopia desktop that might not work with modern Linux distributions and doesn't look very attractive when it does.
There are some games, which provide moderate entertainment value, but do invest in a screen protector if you play any of those that need the stylus to use (some can be played using only the control wheel).
Visiting the several sites on the internet that offer add-ons and customisation options is a must for the technically minded user.
Given it's several drawbacks (and there are others I haven't gone into), you might wonder why I would give it four stars, simply for the amount of use I have got out of it and the overall reliability.