We just got back from a wonderful 8-day trip to Bhutan in December, 2016 with Heavenly Bhutan Tours. There were 7 in our group, 5 from Brazil and 2 from the US, and we visited Paro, Thimphu, Phunakha and Phobjikha. A real highlight of our trip was the Druk Wangyel festival at Dochula Pass. The queen mother and one of the Bhutanese princesses were there and came by to speak to our group and welcome us to Bhutan. Seeing the traditional dancers with Himalayan peaks > 7000 m in the background was absolutely amazing. I highly recommend attending a festival if you can fit it into your trip to Bhutan.
Another highlight was of course the trip to Tiger's Nest monastery. It is a long trip up, but the light is better in the late afternoon so there is no need to rush if you want to take good photographs. I should also mention that we were in Bhutan for 8 days and did not see one cloud. Although it was a bit cold at night (32 F), from my perspective December was an excellent time to travel as there were very few tourists, we got off-season prices, and the weather was perfect for photography.
Our guide Mr. Sajan Rai, was absolutely fantastic with our group the entire trip, and he was amazingly helpful at Tiger's Nest, as he carried all the water, 2 additional bags and helped some of our group up and down the stairs! I really need to praise Heavenly Bhutan Tours for their professionalism and excellence during the planning and execution of our trip. Raju was very communicative with our myriad questions prior to our arrival, and our guide Sajan and driver Loday really went the extra mile to answer all our questions and assist our group. They invited us to a bonfire the final evening and really made us feel like family.
The only concern I had, which has been noted before on this forum, was the condition of the roads east of Punakha to Phobjika, and the lack of good bathroom facilities en route. This is surely not HBTs fault, but I hope that Bhutanese tourist agencies are letting the tourist council know about these issues. I would not recommend a day trip to Phobjikha, you need to spend at least 2 days there to justify the 4 hours of bouncing around to get there. I would also think flying to Bumthang would be a better option than driving if you wanted to see that region, at least until road construction is finished in a few years.
Thanks again to HBT and our Bhutanese hosts for a wonderful trip!
Some photos from our trip in the link below if you are interested: