@R3nAknyght At least when you see it written, you will know what it is how and how it's pronounced (assuming you know English pronunciation, which indeed often is knowing, less deducing or guessing). When you hear someone say an English word, there indeed can sometimes be a two or maybe even three possibilities, though you'd be able to make educated guesses based on the context and such. I'm sure if you are intimately familiar with Japanese and the Japanese culture, you might also know that some name would have 3/4 chance of being written one way, the remaining 1/4 being the more rare alternative (if the parents were chuuni).
That being said, it's a well-known fact that pronunciation ambiguity is the English language's one and only weakness. Otherwise it's surely among the simplest languages of mankind. It even sticks to the basic A-Z alphabet with no extras or modications whatsoever (unless you are a snob and want to write loan words with diacritics).
Ironically enough my native language has extremely simple pronunciation but nearly everything else is very difficult. When you think about it like that, the English languages' strengths and weaknesses are partially wasted on me and my countrymen. So, if you say I know English well, I'm pleased to thank you for the compliment!