Trekking in Bhutan is different from other regions as it associated to Buddhist Culture and Traditions even in the high mountains. The rich coverage of forest along with rich flora and fauna makes the trek more beautiful.
The trekking in Bhutan is lead by the qualified trekking guides and the trails are generally good conditions and if you are fit and experienced walker then there should not be much problem in navigating your self on those trails. Meals on those treks are good, as hot lunch is prepared during breakfast time, packed in hot lunch boxes and will be carried by potter and serve you when its lunch time. Animals such as horses and yaks are used to carry the trekking haulages and your luggage. And no foods are sold on trails, so trekking in Bhutan involves lot of luggages. A typical group of 8 member will have 4 staff, 3 horseman, and around 20 horses. So this makes trekking in Bhutan bit expensive.
Generally trekking in Himalayas are considered hard and one need to be super fit. But there are treks taht catter to all different level of fitness; easy to tough, short to long, lower elevation to higher elevation so you need to choose the trek that suits you so that you enjoy while trekking.
Over all the trekking in Bhutan includes long days with several ascents and descents every day. The valleys are pretty steep and trails are used less as population is less as well as less number of tourist trekking too.