This design lets more air flow through your helmet, which actually improves your aerodynamics
The chest straps, however, are a little on the fiddly side, mainly because the hooks are so small, and we found these were difficult to open and close with cold or gloved hands
For such a modest price, I found the X25 impressive
BAGS : Rockgeist seat pack to store Firepot dehydrated food, MSR Pocket Rocket Gas stove, inner tubes, Noronna Trollvegen down jacket, Norrona Fjora dri Pants, Noronna Lyngen Gore-tex Jacket, Zefal Top tube pack for snacks and tools, Camelbak 710 ml Bottles, Miss Grape Ilcoso handlebar bag mount with Trunk 16 WP bag which contains Outdoor Research Helium Bivy, Therm-a-rest Neo Air Xlite Large sleeping pad, Cumulus X Lite 200 sleeping bag (0-4C), craft thermal underwear in merino wool, Garmin 1040 Solar GPS, Supernova MY99 Pro lighht, E3 Tail light 2, K-Werk Busch and Muller power bank
Its carbon components reduce weight meaningfully compared to heavier budget combos