VIVA is a fairly new series to us. We usually use Lonely Planet or Rough Guide. I was quite impressed with this guide. Well organized, good maps, seems to be pretty complete info. Since we haven't traveled to Nicaragua yet, I can't review accuracy, but we will certainly look at VIVA for future trips.
I've only had this a few hours. I bought the Kindle version and there is no table of contents or index! The information looks good, but this isn't a novel, to be read from beginning to end - it's a reference guide. I literally have to leaf through each page to find anything.