chaining jquery then vs jquery always

always.js

var start = Yapp.promise(function(deferred) {
  console.log("Resolving chain part 1")
  deferred.resolve()
}).always(function(){
  return Yapp.promise(function(deferred) {
    setTimeout(function(){
      console.log("Resolving chain part 2")
      deferred.resolve()
    }, 100);
  })
}).always(function(){
  return Yapp.promise(function(deferred) {
    setTimeout(function(){
      console.log("Resolving chain part 3")
      deferred.resolve()
    }, 25);
  })
})

// Resolving chain part 1
// Resolving chain part 3
// Resolving chain part 2

then.js

var start = Yapp.promise(function(deferred) {
  console.log("Resolving chain part 1")
  deferred.resolve()
}).then(function(){
  return Yapp.promise(function(deferred) {
    setTimeout(function(){
      console.log("Resolving chain part 2")
      deferred.resolve()
    }, 100);
  })
}).then(function(){
  return Yapp.promise(function(deferred) {
    setTimeout(function(){
      console.log("Resolving chain part 3")
      deferred.resolve()
    }, 25);
  })
})

// Resolving chain part 1
// Resolving chain part 2
// Resolving chain part 3