I started diving with the Diva and quickly learned to hate it. It never fit me right (and it was "fitted" before I bought it), I hated the bulk, and the cumberbun was simply too wide for my figure. I now dive with a Zena and love my BC. Plus I"m a rather minimalist type of diver, so no bulkiness is heaven to me.
That said, if your wife loved the Diva and it fit her well, she should have no hesitation in buying one. The Diva is an extremely popular women's BC and a lot of women love them. They key is to find what fits HER, period.