In recent years the standard of accommodation available on most of the Everest trek routes has been transformed out of all recognition. The scale of the construction work has been immense and from simple peasant huts the lodges have developed into larger and larger hostel style accommodation. All now have running water and toilets internally, most have electric lighting in all the rooms, and certainly in the lounge, and some are even now offering en-suite rooms.
However, the further you get from Lukla the more basic you should expect the lodges to be. Namche is the exception with hotels, such as the Hil-Ten, (they love to plagiarise hotel names) offering really excellent rooms.
Wherever you stay though the furnishing is still very spartan and you will find your room generally has little more than a bench bed and a thin mattress so your own good 4 season bag is essential.
We have an approved list of lodges we work with all of which we have inspected to ensure they offer a good standard of room and are clean and well kept. At busy times we send a porter ahead of us to book the required rooms for the group as rooms cannot be booked in advance.