I agree with you on iPhone (god, just looking at that UI in screenshots makes me feel inhibited and unable to make **** work the way I want). Android OS, I feel is a little better, but I've never used either enough to know how much better.

Maemo 5 - well, I don't know how OS2008 worked, and maybe it was the best thing ever, but I myself am not feeling like Maemo 5 is bad. MeeGo - yes, MeeGo worries me. On the other hand, it is, at least in principle, going to be ENTIRELY open source, so no matter how badly every mobile device is ****ed up by the people releasing it, you know that it'll be possible, albeit with some effort, to make it work the way a proper OS is supposed to.

On the other hand, knowing American carriers, they will do everything they can to make it impossible to improve your device - unless they actually collectively develop a sense of being ethical as a company - which is unlikely.

As far as I can see, yes Maemo 5 is not really flawed in the way you mention Android and iOS as being. Browser is very good at doing full desktop webpages, advanced settings can be accessed through the about:config page. And you have Digia @Web, which isn't perfect, but it works (including Flash without needing to enable it in the settings as with the Firefox port, making it the only non-native browser to readily do it that I can see), and it renders pages like on the desktop. As I understand it, the mobile Firefox renders things desktop-ishly too. Java is really the only bad offender in this... Maybe Shockwave too, but I rarely run into that nowadays. Java, both ME and SE, is ported to the N900 already, it's just a matter of making the damn thing work in-browser.

Application switching, in my eyes, it damn good in Maemo 5, not sure if it's that much better in Maemo's earlier versions.

I haven't seen Maemo lock you down to specific coding languages - or lock you out of any - but yes, other OS's are horrible in that regard. (Palm OS is supposedly pretty good too, as are a few other the other not-well-known smartphones.... *Shrug*)

Hopefully MeeGo will go the way of Maemo, or at least is made so that it's extremely easy to make it that way if the makers decide to implement it dickishly.