Kaziranga to GHY Bus service is very good.
if you want to enjoy Rail, then Get down at Raha (on highway , near Chaparmukh after Nagaon Bypass). it will take 10 min to CPK by share auto.
The train Kapili is Puncual.
U can enjoy River Cruise Restaurant in Barhmaputra River at Facncy Bazar/ Sukreswar Temple near GHT stn