I have a L920 and iP5s and I'd say the differences fall into hardware and software camps.
Nokia's phones are unique in their designs, whereas I tend to see Apple, Samsung, HTC etc as following the same design principles. Nokia also have made a champion of design and their phones are easy to spot from what otherwise would be a fairly similar line up.
On the software side, Nokias come with HERE maps, and DRIVE etc., along with a fantastic camera and inbuilt photo editing apps, Office and good MS integration.
There are some woeful downfalls as well though - albeit that some of these will be addressed in WP8.1, such as the hopeless calendar and poor notification set up, both of which are weak efforts for something billed as a work phone...
I have learnt - the hard way - that there isn't a perfect phone. The best one for me is the one that can achieve the most of the list of things I need it to do....