It has awfully slow run between SVDK and NDLS. Too many halts. You won't be awake to get a breathtaking view of JK. NDLS onwards speed substantially increases. It would even touch 113 kmph even though limit is 110kmph. Don't think of travelling into sleeper class, I couldn't even pass through a coach, it was that jam packed. Your back will start to ache after around 30 hours, so stretching is recommended after getting down at any railway station with halt of more than 5 minutes.