Works well for me, I bought it as a last minute "oh-hell-I-need-a-flash-because-the-person-who-was-going-to-lend-me-their-430EXII-decided-to-be-a-git-and-change-their-mind"
I had a gig to photograph, and the photos came out great, I wouldn't have seen that much improvement if I'd used a 430EXII, in my opinion.
Go for it, it's about £80 if I recall correctly. Get some decent rechargeable batteries and you're all set. (eneloop ones seem a popular choice on here)