Handspan Travel is an amazing company offering a very professional, high quality and friendly service.
Yes their tours are more expensive than other companies, but I sincerely doubt you will find the same high standards elsewhere.
We hired a 4x4 through them for 2 weeks going around Northern Vietnam. Admittedly it was very expensive, but it also was the highlight of our trip. Our driver was totally friendly, patient, efficient, punctual and helpful, even though he didn't speak much English. He was happy to do whatever we asked for and always did it with a smile. Our vehicle, a Ford Everest, was first class and brand new. We honestly couldn't have asked for anything better.
We also did a 2 day cruise in Bay Tu Long Bay (Halong Bay's equally amazing but non-touristy neighbour), and again everything about it was outstanding: our Lagoon Explorer Chinese sailing junk was totally luxurious, the 7 fresh seafood courses were heavenly, the guide was friendly and spoke good English, and the staff on board were great.

Handspan sets up biking, hiking, kayaking and boat trips.  We did a 3 day bike trip through them in Northern Vietnam. Visited hill-tribe markets and mountain biked, it was amazing. We also did a kayak/boat trip in Ha Long Bay and it was also fantastic.  They are professional and thought a little bit more expensive than some of the tour companies, but I think they are worth it!