I just finished the Royal/Skyline trek set up by this agency. Everything went according to plan and there were no problems with the agency - Nava is a friendly, helpful man (the owner), and this agency has been around more than 20 years, so it's not a fly-by-night business. And the guide, Tek Niarula, was fantastic. He was always helpful. Informative but not intrusive. Genuine at all times, going the extra distance to make it a good experience. And has a great sense of humor. A real pleasure trekking with this man.
However, I do also need to say that I would not recommend this particular trek. There is a new road going around almost the entire trek course, so one didn't really get that trekking feeling. It's a new road, just a couple months old, many parts of it, so it wasn't Nava's or Tek's fault about that. Just passing on information.