Implicit returns encourage functional style; foo.map(|x| x + 1) is so much nicer than foo.map(|x| { return x + 1; }). Once you have implicit returns in closures, you might as well have them everywhere for consistency.
Good
fn inc(a: u32) -> u32 { a + 1 }
fn foo(a: u32, b: u32) -> u32 { let x = a + b; a * x }
fn bar(...) -> bool {
let mut success = false;
let conn = getConnection();
...
if x > y {
return false;
} else if z < q {
success = false;
}
foo.barify(x, y);
...
success
}
"Nicer" is a subjective thing. BTW in the trivial case above one may judge this or that to be nicer, but in a large method, 'return func(a,b,c)' is obvious, whereas looking at 'func(a,b,c)' it is super non-obvious that the value is being returned.
Then "foo.map(|x| :x+1)" is nice. If that doesn't stand out enough for some people on a line of its own, make your editor render the unary colon line in a very bold color for you.