I used the ROUGH GUIDE TO NEPAL for a six-week trip through the country in December-January 2013. It was my second time there, and during my first visit three years before I had used the Lonely Planet guidebook. Having become unhappy with Lonely Planet's move upmarket, and the fact that whatever downmarket accommodation it recommends tends to draw too large a crowd and consequently lead to price increases, I wanted a change. Rough Guide's offering for Nepal does recommend a lot of places distinct from the Lonely Planet. Prices were reliable, though if you are staying in a place more than a couple of nights, it is usually worth bargaining for a rate slightly less than what the guidebook would have you believe.
But the great strength of THE ROUGH GUIDE TO NEPAL, I found, is the enormous level of background on the country, so that tourists can understand the society they are travelling in, not just look at attractions. Nepal has a lot of problems: poverty, gender imbalance, and the fact that the educated are drawn to the Kathmandu valley, leaving the countryside without doctors. The Rough Guide takes a sober look at all of this, and it tries to be fair. For example, it examines both sides of the debate over whether the massive roadbuilding projects improve the people's lot, or whether they just allow India and China to flood the market with their goods and out-compete local producers.
If you are looking to trek, the ROUGH GUIDE TO NEPAL has fine coverage of the most popular treks and even some obscure ones. Trailheads tend to change as roadbuilding continues, and this edition proved up-to-date at the time I was there. There's also a lot of information about mountain biking, though from experience I've found that the Kathmandu and Pokhara valleys, even outside the urban area, are now too polluted to cycle.
Downsides? The book doesn't mention that you can bargain with teahouses on treks. In fact, it doesn't mention at all the great problem of corrupt local tourism authorities, dominated by big lodge owners, forcing all lodges to give the same printed menus with set prices. Not only do those set menus risk making trekking too expensive for more and more backpackers, but the same prices everywhere makes it hard for the small lodges to compete with the big ones with their hot showers and internet access. Another problem with the Rough Guide is the binding: it started to become loose just a few days into my trip.
Unlike another reviewer, I didn't find the maps to lead me very astray, but getting slightly lost once or twice in a city is, in my opinion, a good thing as it leads to nice surprises.