These coach will be used for overnights where people has nothing but just to get in and sleep!!
I think leg space is compromised more than GR (which got Berth Count raised coz of SMB) but it's Fare allure SL & 3A travelers!
But 3E with this price tag, will make traveler switch back to 3A while Sleeper traveler may not switch to 3E but will find other SL train!!