It's just a game of 3-4 years. GS SL, everything will keep moving aside. All trains will become like AC Express.

IR wants to replace GS economy, ACC, and SL with 3ACE. They said during the design phase that the AC temp will be at an optimum 24 deg C. The 3ACE has many added features like individual AC vents and USB chargers that should be given in 2AC and 3AC. The berth should be designed with the end towards the window naturally raised to act as a pillow. The blanket should be carried by passengers like in non-AC sleeper buses. The fare of 3ACE should be in between SL and 3AC but they priced it 5-7 less than 3AC which made passengers think bedding would be provided. If bedding is avoided, IR will save Rs 30-50 on each berth for washing linen and attendant salary. ACCE should be priced at SL class fare to upgrade GS travellers.