Not any more. Both seem to fit my oval Frankenstein noggin equally well. That characterization about differences between Bell and Giro fit predated the merging of the two helmet makers under the same umbrella corporation in 2016. It appears Giro changed some of their designs. The comparable Giro helmets I tried at REI last year fit identically to the Bell Formula MIPS I bought. I'd have bought the Giro if it had been available in the color I wanted.