@Flight; I'm not sure there is a "advantage" in Simba itself but if you are interfacing with another language or plan on communicating with another API, then binary serialization IS beneficial.
For example, in that link Cynic linked above, you could easily just write the Bitmap string to the file and when reading it back, you do BitmapFromString.. However, instead of doing that, he chose to write every pixel to the file in binary format. Advantage there is that someone else can just read the pixels from any language/api and be able to use the image too without having to write Simba's internal algorithm for interpreting bitmap strings.. If you can guarantee that this information isn't used by anything other than your script and no other programs, then there is little advantage to binary serialisation.
That is the advantage. Simba-wise, there isn't "much" but there is a little bit. One such advantage is that reading is simply the opposite of writing.
If you noticed in my example, writing is way easier than reading. Writing is a couple lines long but reading requires a bit extra work. With binary serialisation, the way you write is the exact same way you read. It's also good for POD structures (Plain Old Datatypes)..
Write one byte, read one byte. Write one int, read one int, etc.. - Binary Serialisation.
Write a one byte, delimit, write another, delimit. Write one int, delimit, write another.
Read until each delimiter is reached, reinterpret that data as the correct type, rinse and repeat. - Plain Serialisation.
Binary can be smaller in terms of bytes and is native. Example: 0xFF is 255 in binary. It takes up 1 byte. 255 in plain-text is 3 bytes aka 3 digits. Binary require more knowledge of language and bytes and structure.
That is the differences. Whether it is an advantage in Simba is highly debatable because there isn't any interfacing or outside communication going on.
Just choose whichever suits your needs.. There isn't really a right or wrong.
http://stackoverflow.com/questions/2364581/binary-vs-text-protocols