Argument size was a limitation of the product that limited the buffer sizes that were used for string manipulations. Buffers now dynamically managed. And they're automatically managed by the runtime. So you don't have to set argument size and get argument size to get around these limitations.
When you use it argument size or get argument size. And if you still do, it will just not do anything. So you can still share code between different versions.
Can be used to define constants strings that can span multiple lines.
You do this by putting the @ symbol in front of your string, then you can have line feeds within this string. These line feeds will end up in the actual string, when you use it within your code. It will not do compiler substitutions. So compared to the regular string, that's another improvement. You can use the string type for embedding SQL, HTML, Json and all kinds of multi line things that you would like to embed.
We now have a non linguistic mode for sorting arrays of strings super fast compared to doing it in a linguistic manner. And we've made some improvements to the DateTime type. Were conversions between date, time and variance now maintain milliseconds.