I'm going through the same questions and doubts myself, currently.
I need to replace my aging helmet (Giro Bad Leutenant, size L, which I love despite the lack of air intake and circulation), and double the quiver.
Need :
-"Racing" helmet.
This will be primarily used during training and racing (if and when I will re-enter the actual racing arena and not only the training in gates part, is still to be seen, but at least one race, I will have to take part into, so I need a FIS vouched helmet for that)
I set my eyes on the Briko 6.8 Protetto, alas w/o fluid system (USSA colours, I am not American, but "Old Glory" colour scheme has been, when racing, with me since my early (teen-age) racing days, so the colour scheme seems only fitting) , problem : my melon size is closer to 59, available sizes are 58 or 60...should I go smaller or bigger (and then use a thin cap to fill, if neded) ? I tried a size 58 and the back of my head (not to mention the forehead) felt too exposed..couldn't try a 60 and if will decide for it I will either have to buy it online or wait till next season-
-Everyday/freeriding helmet...I would really like to get a Sweet protection (with or w/o brim, better if removable, though) melon saver here, but they are hard to find...what other options (I tried Oakley Mod3 and Mod 5, they fit ok but colours available are ugly) are available?