Dear Rohan ,
Your statement "So whenever speed change has to be much depends on the skill of the LP otherwise passengers can have jerks in journeys." is absolutely Correct.
Four Times in my Life I have found this Tremendous Jerks in LHB Coaches & also my Co-Passengers are suffered much for that
The Dates & Times are as follows:
June...
more... 2014: 12259 SDAH NDLS Duronto (Delayed by more than One Hour but departed on right time) Loco was HWH WAP-4
June 2014: 12260 NDLS SDAH Duronto( Delayed by two hours but departed on right time) Loco was HWH WAP-4
May 2015: 12277 HWH Puri Shatabdi( Delayed by more than two hours & departed 1 hours 30 mins late) Loco was VSKP WAM-4
Nov 2012: 12261 CSTM HWH AC Duronto Exp( Delayed by Five Hours) Loco was HWH WAP-4
Conventional Locos are dependent on the Skill of LPs .
You can see the main limitations of WAP-4 in the following BLOG & why WAP-4 is not so popular to the Lp's in the following BLOG
/blog/post/1409017/0For these Limitations 3-Phasers are much preferred choice over conventional Locos.