Just returned from Luxury Everest Trek. Third Rock is immensely great for organizing treks in Nepal. We didn't expect such level of service from them. They have local guides with huge deals of knowledge for the trek. They offer you the best available room, and foods are great too. Naba in Ktm was keen to know about us and would update every now and then. THe guide are energetic and welcoming. Please do check them once if you are planning for trek in Nepal.