It depends! If you can reach early at CSTM & want to enjoy Legendary train ride but with dirty coaches, jam packed public in reserved coaches then Geetanjali is OK but if you want travel in clean coaches with less stoppage but odd time to reach at Howrah then go for Jnaneshwari.
I suggest, don't go for train name, it depends upon purpose of trip, how much time you have & last but not least is availability of seats.