Spot on. I have been 5 times now, since 1981, and am sure I will be back in a few years. I have done the Annapurna Circuit 21 days, Annapurna Sanctuary 8 days, Langtang, Helambu and Gosainkund Trek 20 days and Jiri to Everest Base Camp via Gokyo (28 days) and back to Jiri. W did all treks solo relying on the tea houses for food and bed. The Nepalese, despite their hardships, are the most welcoming people I have encountered.
The Everest Base Camp trek was the best for me. Trekking in from Jiri takes 7 days to Lukla airport by which time you are acclimatised to the altitude of Namche Bazaar. Did it in December as the massive groups had stopped for the season but had -15C nights but T shirt weather in the day and clear clear skies. EBC is better in my eyes because you spend so much time above 5000m and the scenery is the most impressive. In fact out of this world.
Langtang has a murderer, who has attempted to rape a number of solo women trekkers. Two missing for over 2 years and a young Belgian woman found decapitatd a couple of years back. The Government were going to stop trekking without a guide due to this but backd down. Apart from this trekking is as safe as can be in Nepal.
Trekking solo gives us morte independence but having a porter and guide gives money to the local economy. To counteract this we donate to the Himalayan Trust started by Ed Hillary.