When I switched from Siemens to Ericsson T39, it took me ten seconds to figure out the whole menu system. Very easy! When I tried a Nokia phone, the menu system confused me for hours...
(But now that Nokia has copied Ericsson's icon-based menu system, even I can use a Nokia...)

Another reason to use the T39: When you're sitting on a train moving through sparsely populated areas of a country, that external antenna is sure good to have whan you're trying to make a call. Nokia phones only work well as long as you are close to the base station.
Nokia are good at marketing, but their technology sucks!