I also download from Planet Elder Scrolls (as Morrowind Summit later called itself) because it hosts large files, has reasonably fast download times and, again, I feel reasonably certain it will be around the next time I'm looking for a mod.
I do not like TES Nexus because it is unfiltered. Anybody can upload garbage to TES Nexus on a whim, and do. Some use its uploading capacity as if it were a filesharing site ("If you are not Bob don't download this file"). There's too much junk to wade through on TES Nexus for my taste. This is not TES Nexus' fault, per se. It is the fault of modder who want instant uploading gratification.