My wife and do a lot of urban riding - mostly on bike lanes - and usually we don't wear a helmet for these rides. But I'd like us to start, and I'd like to get her a nice helmet, one that doesn't look like a standard bicycle helmet. I found a couple of companies that make the sort of thing I'm considering - for example - Yakkay, Nutcase or Lazer. Other than being more expensive, do these helmets have serious drawbacks? We live in a pretty hot, humid climate, so ventilation is definitely a concern.
Some clarifications:
I want to point out that even though I described it as "hot and humid" here, lots of people - probably a sizable minority - do ride with helmets. I ride with one on the longer rides, but I have a habit of skipping it for the short urban ones. The two of us agree, in principle, about wearing a helmet, but I think she'll be much happier starting with something pretty.
Here is Tel Aviv, by the way.