It is an old joke that the difference in the first class and second class of the Mumbai local trains is that people in first class use deodorants and hence you are exempted from the smelly underarms while travelling. The mute point being; both class of travel experience a passenger overload during the peak hours and you are almost equally squeezed and pushed around in both.
Of course, the seats in First Class are cushioned (unlike the hard seats of second class) but then that would make a difference only if you get to sit (which would be a likely probability only if you get into the train from the station it originates).
My father holds a first class pass from Churchgate to Andheri (since past 7 years, ever since we moved to Andheri). He often travels by Second class in the evening. Strange, isn't it?
This is why he does it … In the First class, there is an unwritten rule that on the seat, only the designated number of people (which is 3) will sit. No squeezing on the seats per se. In the second class, on the other hand, people will move and squeeze to accommodate an extra person so 4 people can sit. When my Dad gets in the train at Marine Lines while coming home, in all probabilities, 3 members are already seated on all seats. In first class, he would have to stand for over 40 minutes of the journey unless he gets a seat vacated by someone; while in Second class, he would get at least the 4th person seat which would translate into proper seating when someone gets up and leaves.
I don't have 'that' facility since I get in at Lower Parel (closest to my office) and by that time the trains are almost fully loaded with people. No space to sit and you got to struggle a bit (just a bit) to find some space to stand. I often get an empty seat to sit by the time the train reached Santacruz but then I often don't take it since it is just 5 more minutes to Andheri. The first class and second class difference is not really much for me except the 'Deo' part J and of course the fact that the crowd is 'little less' in first class … but the crowd is there nevertheless.