Many thx bro 
Both treks have different killing instincts 
Ratti Gali - A boxing match of 11 rounds and u will keep on getting punched for 3 days hehe
Chitta Katha - A 2nd round knockout hard punch 
Ratti Gali needs stamina both physical and mental as trek is long (38km return) and is all the time climbing up. No open valleys so have to trek on slopes throughout which needs concentration all the time.
We did it in 3 days = 12km + 14km + 12km so everyday is tough and long. Start early at sunrise from Dowarian as this area is relatively hot unless u get lucky with cloud cover.
Chitta Katha is more steep climb but distance is half (18-19km return). Start of trek is very tough and then Dak1 is flat for some time. A little climb to dak 2 (easy if no glaciers) and again some flat area. Then the final steep climb to the lake. But this steepness is equally tough to come down.