I don't think one of the editors is easier then the other one in general. For some aspects nile is easier, for other ones med. Med is more powerful though, nile is lacking lots of features, some can be worked around but other cannot. Nile still is an unfinished beta product missing some vital functions used in coop maps, that's why most coop maps are made with med. Optionally with a converter to convert a nile map to med, if you prefer using the 3d view to place objects but set up the ai in med.