This lens is both tiny and lightweight but has true world-class performance at a budget price. I'm really hard pressed to find anything negative to say about it; it does exactly what it claims to do and does it well. An outstanding performer even wide open.
Oh - but I wish it had a sensible filter size (it uses 37mm) and it should ideally come with a lens hood, which it doesn't. That's not really the fault of the lens and shouldn't put you off buying this little gem of a lens, but it's slightly annoying none the less.