Maemo/Meego devices are like a computer that you can put in your pocket, for example the N900. Before N900 these maemo devices had been slow, but thanks to the iphone the whole computer industry has realized the importance of speed. N900 is not slow, what i like about this phone is the keyboard and the great web browser that it has. Just imagine the scenario, you are reading a web page on your desktop and then when you have to catch the bus, that page opens up when you start the browser on your N900. This is possible with the firefox addon called the Mozilla Weave. N900 is just awesome, it just needs to exercise 4 hours a week to lose some extra fat that it has, but other wise I really like it.
But perhaps the best thing about N900 is that my Qt apps that I write for Symbian also work with little modifications on my N900! you dont even need to install some crazy toolchains or use the linux os to do any of this; with the Nokia Qt SDK you can do all of this from your windows computer. Even though its in beta right now; but every thing works; i am using it for a meego/maemo app i am doing and no issues yet