award If you construct and initialize a string variable, there's no benefit. Every time your code hits a var declaration, a variable will be constucted. However, a literal without var is a compile-time constant and it's not constructed at runtime.
When you initialize a string it's totally irrelevant whether you use a regular string literal or a string name. They're both immutable string constants, sitting all the time somewhere in memory. So the following are exactly the same in terms of what gets constructed. A single variable gets constructed and is initialized from an immutable constant:
var s: String = "text"
var s: String = &"text"
const s: String = "text"
var s2: String = s
The only real performance benefit of string names you get is when comparing two string names, or doing some kind of hashing with them.
