Yes we can understand each other just fine. I live in Miami, this is the place where Spanish speakers from all over latin America and Spain converge and we have no trouble understanding each other. My work colleagues are from Argentina, Venezuela, Colombia, Cuba, The Dominican republic and I am from a very rural and relatively isolated part of northwest Mexico and we have no trouble speaking to each other and understanding each other it's the same language just different accents. Since I work for a spanish financial institution our bosses are based in the north of spain and when we communicate with them we can understand each other just fine, so yes we all speak the same language, we just have different accents.