I miss two-barreled water blasters, but this one is meant to have independent control over its nozzles. An under-over design could be fun, too, but somehow the side-by-side arrangement looks more intimidating to me.
One larger, powerful nozzle > Two smaller, weaker nozzles. Dual nozzle designs are pretty gimmicky and IMO as they don't serve much practical use. You could alternate-pulse shots between the nozzles to make it look cool though.