Mark M.wrote a review of Giro Syntax MIPS Helmet on September 29, 2019
Familiarity: I returned this product before using it
My head isn't so much large as tall, and I've always struggled to find helmets that fit: large sizes are wobbly, and anything smaller tends to sit on the top of my head like a bottle cap.
This helmet, though, is perfect—comfortable, with adequate coverage for my tall-above-the-ears head (despite a relatively low profile), and easy to dial into position.
I ended up returning it, but only because I bought a Giro Vanquish at the same time which fit similarly well, and I opted not to keep both. If I were to give up the Vanquish, I'd be back to the Syntax in a heartbeat. Highly recommended.