I heard only good things about Halfeti but never had the chance to test it, until I made a sharing and I was blown away how good it is. For my taste, is quite understated and will not project too much, nut the nice spicy character will last for many hours, even if not loud.
In a span of few years after its launch, Penhaligon´s came with a few flankers which I think are also worth considering.
Overall, the Halfeti smells very nice and expensive and if the old school bottle is not for you, you can get Mr. Sam which smells identical (to me) and comes with the nice personalized bottle.