I sat down a few months ago and did a serious comparison of the budget-focused travel books so that I could order some for my students to peruse as they were thinking about studying abroad. For areas where there is coverage, I opted for Let's Go. Beyond having good maps, the more critical thing to me was that Let's Go gives the best directions on how to get to a place. Most guide books, including Lonely Planet (of which I have several) offer: "This museum is near XYZ subway stop." Let's Go gives you: "Go to XYZ subway stop, walk 3 blocks down Q St., turn left and go another 2 blocks to R St, turn right and it is the 4th building on your left." Maps are great, but directions can be better. As someone pointed out, Lonely Planet does have more extensive covereage than Let's Go, but I'm less impressed with some of the features.