For me, I like it being a good outdoor phone as well (beside everything else already having been said). You can use it with gloves on, replace batteries easily, BlessN900 makes for some decent pictures to my standards.

also the cost of a learning curve and cost of a new device keeps me from moving ot somewhere else. I might buy Ubuntu phone in the future, but I will probably still keep N900 around for travelling (unless they make something with resistive display, accesible batteries and hardware keyboard:-)).