While I don't yet own a Ridgeline, its on order.
I have test driven 3, and borrowed a friends for 9 days, they all accelerated just fine, and were quickly up to highway speed.
If too sluggish engage sport mode, or at least leave in regular mode, and push harder on the throttle pedal.
I've noticed that what some people call sluggish, is caused by their failure to stomp on the right pedal.
Floor a Ridgeline, and it will accelerate darn fine.
Not Ashely Force drag car quick of course, but more than respectable for a pickup.