E ring - would you or would you not?

I would not because that stone is too soft for daily wear. It's gorgeous, just won't hold up. But you love it, so as long as you're aware of the fact that that stone cannot withstand daily wear and are careful with it, get what you love.
 
It's absolutely stunning, but one thing that I would keep in mind for an engagement ring is the hardness of the stone. Tanzanite is a fairly soft stone- much softer than a diamonds or sapphires, which are some of the hardest stones, accounting for their popularity in engagement rings. Depending on how hard you are on your jewelry, it might be too fragile for every day wear. I'd love to hear from people who have tanzanite rings, but from what I've heard, they are easily scratched and shown wear over time. I know for me, I'd be afraid of banging it on something or scratching it.
 
Personally, I wouldn't . It's far too soft to wear daily for a long time. Beautiful ring, but just too fragile.
If you have your heart set on it, would you consider getting a diamondband as a weddingring and then then wear that most of the time ?
Is money an issue ? You could get a a sapphire like that ?
I am not sure what Tanzanites go for. T Co made them famous, they are generally considered semi-precious.
 
It is a beautiful ring, but I agree with the others that it may not be suitable for everyday wear. A sapphire, however, would probably hold up better and could still give you the coloured stone/halo look - unless of course the tanzanite has a special significance. But if this is the one that you truly love, then perhaps it would be worth it to at least have and wear for special occasions.