vikramdhani,
I think skagen has pointed out the things I want to tell. To convince you... I think you need to convince yourself to leave all the bell whistles offered by the N73 behind first. I like it a lot, except the power button (it does not offer a good tactile feedback and the rubber that cover the button can be worn in time) and the relatively smaller font size (due to the fact it has a smaller physical screen compares to other Series 60 models). When I do not need all the optional items like WiFi, 3G, 3MP camera, FM radio, full keyboard that comes with many other models and I want a slim, low-profile, sturdy cellphone for business trips, E50 fits my bill.
Also, you can read some reviews out there...
Steve Punter... very straight-forward and focused on the fundamentals of a phone: http://www.arcx.com/sites/Nokia%20E50.htm
Mobile-Review... more technical but English translation sometimes is not as fluent as the Russian original: http://www.mobile-review.com/review/nokia-e50-en.shtml