one thing that needs to be underlined is the fact that if you use the N900 with its original Maemo 5 / Fremantle (maybe with a few useful applications like unlimited history, individual ringtones, recaller or so) the N900 is a perfectly fine phone;
not quite as elaborate as a N95 or a 9500, but certainly better then an iPhone or any ANDroid device, as far as (phone) functionality and having your phone fully under control are concerned.
start adding power-kernel, Community Seamless Software Update (aka CSSU) and the like & get ready to have the device crash / reboot in the middle of a phone conversation
ultimately it is up to you to decide whether you want a phone (which seems to be what you are looking for (?)) or a geek's toy, indeed.
keep in mind that the phone is over two years old and that the last firmware update (PR1.3) was released nearly a year ago: the CPU runs @ 600MHz, it has only 256MB RAM and the browser only supports Flash9 and doesn't support JAVA, to give a couple example