If you have to book b/w 2A and 1A in this train, go for 2A even if it is in RAC or couple of WL. The 8 1A seats are always almost empty. Once, I saw only one seat booked, back when booking lists were pasted. When I personally traveled in 1A of this train, the person next to be had automatically been upgraded from 2A, again showing that 1A almost isn't chosen at all.
The train gets often rescheduled from LKO and sometimes from NDLS as well. Often used by pax...
more... of intermediate stations. 2S and even CC is full of unauthorized standing [and sitting on floor, in case of former] between CNB-GZB on this train. Except HA1, no coach is untouched.