Do you wear a helmet? You should, I must confess I don't all the time, but I insist everybody who I teach at beginner level does. If you don't wear one why? In the old days they were heavy and made you look like a dork, today they are much better and attractive. Reasons for wearing them are less.
The Harder shelled version is more durable and less worrisome when your baggage is not in sight or with careless users. The HS also has less ventilation holes so is potentially warmer!
TheStealth is a very good helmet I prefer it in version 198 grams because I am a minimalist but its worth looking at in the slightly heavier version.
Even my hard as rock head needs protecting sometimes.
The Stealth comes in a Carbon shell but unless you are very wealthy the normal versions are the war to go. I don't like to say you should wear a helmet, but I think you should consider it. I always wear one where things could hit me, falling ice, climbers dropping gear. The yellow one protects you from the sun a bit and is a good hot weather in the sun helmet. The Hard shell version is white and might be an even better hot weather helmet. The choice is yours.
Grivel Stealth Helmet comes in Yellow and Titanium. The Stealth comes in a harder shell for more durability, this is called StealthHard Shell (HS), it is slightly heavier but will prolong the use of the Helmet.