Forget the tourist uniform of backpack and Lonely Planet/Rough Guide in hand.... you're going to need both hands to carry all the 'bargains' that the salesmen of Marrakech have so considerately helped you spend your money on!
This is a tremendous little guidebook to carry in your pocket as you wander round Marrakech.
The old Medina is a rabbit-warren of alleyways (you WILL get lost, so enjoy the experience!), so to have a well thought out little book like this on you is a real help. It is just the right size (and weight!) to slip into the leg pocket of your combat trousers or back pocket of your jeans, and has just enough practical information about sights of interest, shopping, restaurants etc etc, to keep you busy. I found that whilst I do have an interest in the politics of 17th Century Morocco, I was quite content to leave my full-size, full-on guidebook at the hotel for a bedtime read, and just go for a walk to see what I could see.
This book is different from many others in that it is organised by neighbourhoods, each with a detailed map of the area. I found these maps to be significantly more use than most I saw, as you will need to navigate not by street signs but by landmarks, and these maps are full of helpful landmarks (what signs there are- and they are fairly few and far between!- are mainly in Arabic of course). They are also not fold out maps, just pages in the book, which makes using them quicker and easier too.
My only real criticism is that I would have liked to see more information on cheaper places to eat in each neighbourhood. The suggestions they do have were often a little pricey, and in my opinion- in Marrakech at least- pricey certainly isn't to be equated with better; the best places I found to eat (very) well, were also the slightly more rough and ready places, which perhaps this guide's authors didn't care for!
I always find Lonely Planet books the best laid out and easiest to use. Their full-size 'Morocco' guide has a rather brief, if helpful, section on Marrakech; and their 'Best of Marrakech' guide is very good too (with a lot of the information duplicated in this book), but the excellent layout and design of this book, not to mention it's physical size, shape and weight, gave it the edge for me.