Length is the same It's only the width of the coupe berths and leg space which is decreased. The side berths arrangement is same that of SL which start right from the door and end right before the door. 3ACE is designed for SL passengers to upgrade to AC classes and not for 3AC to degrade they should upgrade to 2AC for comfort and should not complain. One mistake the RB has done is stopping 3AC production citing bedrolls provision in 3ACE and fixing of fare 7.5% less then 3AC which should be 20-25% cheaper.
Members...
more... here want SL passengers to shell 60-70% more to upgrade to 3AC citing non profitable and subsidised but 3AC still be 3AC and not upgrade to 2AC paying 30% more. The number of 2AC coaches have increased from 1/2 to 2/4 and 3AC from 3 to 6 min and have more berths for LHB fied trains by addition of additional coaches.