From my personal experience on living, trail riding and exploring Baja starting on basic compass and Baja Expedition map on my car, to garmin 38, 45, garmin II, garmin III, garmin V and presently my trusty 276c and 60cs that i switch back and forth beteen bike and truck.
U have all maps available for Mexico.
Fort the most accurate and most up to date Topographical of Mexico, nothing and i mean nothing beats E32 maps. I recently upgraded to the 2010 revision and the WOW factor is amazing.
Again only way you can tell is to do a comparison betwen all masp which i do own and on my bike i toggle between bicimapas and e32 when i am on in Tijuana, Tecate and Ensenada but when the pavement ends...
E32 all the way. I have a place down in valle de guadalupe and recently 7 riders rode from my house to rancho Melling at sierra San Pedro Martir to wartch this years Baja 1000. We did the traditional ride that most off roaders take between Ojos Negros to Mike's and beyond and next day rode the coast doing the race course and being passed by many leftover participants that were way over due to the finish line and the accuracy of the maps is spot on.
Hope this helps anybody that likes exploring baja .