I looked at the Davida helmets, but had concerns on price for safety. The really retro models (classic) look great, but the impact aborbing material is cork and their website states "The Davida Classic Helmet does not conform to any current helmet safety standards."
The 3/4 Davida helmets (Classic Jet, Ninety-One) do meet various safety standards, but others make 3/4 helmets that cost less and have the more recognizable DOT certification.
I use a Bell half-helmet when commuting or for a retro look. Looks good with goggles:
drifter