You can gain 99 leves. If you have that many and time, you can do them all in one day. You can hold a total of 16 leves. After which you can go back and pick from the remaining leves of the 99 you had to choice. Grand companies or for the most part similar. There are some differences but not much from what I can see.
Unfortunately I play on a different server. It's a mix community, but you can find English speakers. Excalibur is my server