I suppose I should've clarified: I meant to say that I was wondering if it would interfere with the back of my head and my neck when I am looking upward from the drops (I am only crouched really far over if I am going down hill at speed. For reference my bars and my seat are about even in height; I'm not upright or anything, but by no means is my back usually flat in an aero position.)
Why would you want a heavy brain bucket? My wife bought one of those Nutcase urban/skate helmets. After two weeks, she bought a road helmet and hasn't looked back. It was heavy and it affected her peripheral vision.
If you're going to get one, also make sure you have a mirror. They really do have an adverse effect if you turn your head to look behind you.
Oh, and one last thing---they offer no additional protection over a standard road or MTB helmet. In fact, the Nutcase helmet finished dead last in recent Consumer Reports ratings for impact protection.
As far as weight is concerned, the giro one I looked at was only like 260 or 250g, thats lighter than the bell helmet that I had. Furthermore, I'm riding a 30lb low end bianchi from the 80's, and that is before I add my commuting pannier. The extra 1/4-1/3 lb of even a 400g helmet would be no issue.
The Giro Reverb suffers none of the ill effects of your garden variety skate helmet. It's lighter than my road bike helmet. Peripheral vision is not effected. It even comes with a removable cloth front visor. And it looks 10,000 times less dorky than a modern roadie helmet. Lots of color and pattern options. Much better air flow than my old Bell road bike helmet. Giro did an awesome job designing the Reverb. Nicely priced too.
Right now I think I am looking at either the Lazer tempo or the specialized align based off of availability at lbs and a swaying towards the non-urban styles because I'm not a fan of what they have in stock. From what I can tell, they are both pretty similar, and will cost me the same either way, and both have reflective areas.