The Giro looks good. I would definitely consider that- more vents and looks more 'sporty'
The thing I don't like about the Brentwood is the padded headband/visor is quite thick. If you pull it out, it's a full size too big.
I wish they used thinner padding or just a visor. the padding also put pressure on my temples, there is a snap located right there.
Brentwood is thinner than the Nutcase and lighter. The fit is different so maybe go for the one that is most comfortable.
For me, the Nutcase was more comfortable. Also like the fact Nutcases are durable- you can toss them around and not worry too much about it.
Also be aware that Brentwood sizing is way off other helmets. I believe a SM = Brentwood Med, etc. Probably because of that padding. So measure and use Bern's website for sizing measurements and try it on.
I honestly don't use them and prefer racing helmets. Much lighter, better venting. They don't look any more or less dorky to me.