It is always better than an American dictionary.
One can always expect to find American usages in it.
One can never expect to find American usages in it.
It tends to include more grammatical information.
美国词典在正文中比英国词典包含更多的百科信息，比如名人的名字，历史名胜之类。英国词典，特别是学习者词典，包含更多的语法信息。
