I once had the sweet fortune of traveling in this train. In true classic IR fashion, it started 3 hours late from Sealdah at midnight. Most SL passengers deboarded at Jamalpur and Bhagalpur. I was the only person in my coach to do an end to end journey. The train became effectively a passenger train with unreserved crowds in the sleeper coach. It halted anywhere and everywhere it could including at all stations in Patna( except for Sachiwalay Halt). But since its TT is even slower, it made up for some delay and reached BSB 1.5 hours late. I had a connecting train from BSB at midnight which I caught (though CPR LJN Express is a crawler in its own right).