Well, If you hear the different accents you will understand more or less. However, there are some particular words from each country.

In my opinion, the big difference is in one pronoun and how it be conjugated according to the verb. In the second plural pronoun, the Spain people use "vosotros" meanwhile people from latinoamerica use "ustedes", Similarly the verbs changes acording to the noun. If you want to conjugate the verb "to walk = caminar" , will be like this: Present Tense Vosotros Caminais ----Ustedes Caminan Past Tense Vosotros Caminasteis----Ustedes Caminaron Future Tense Vosotros Caminareis-----Ustedes Caminarán the other pronouns are conjugated without variation between both regions and the other differences are the means of some words

Yes. There are differences. That doesn't mean that a latino can't understand a Spaniard. There are many subtle differences. If you are serious about learning Spanish, you will easily pick them up.

take a look on this http://www.italki.com/article/224/ustedes-vosotros-vosotras-and-you-second-person-plural-pronouns-in-spanish#.VXKTAs_tmko