Yeah, they say that on the workhorse chassis section too. But then some of them have taken their koni's off and gone back to bilsteins because they handle better.
The koni's are not gas-charged and there's very little (or none) compression damping to them - it's all rebound. So they tend to soak up the sharp bumps a little better but don't support the coach as well for slow speed compression damping like cornering. Some said the coach will sway a little more back and forth on driveway aprons, uneven surfaces, etc.
That's why I said you'll like the bilstiens. For three times the money or so, the Koni FSD's are definitely an option.
In 2005 Workhorse updated their chassis' with Bilstien shocks to improve handling. Koni's are a relative newcomer to the scene. Both are reported to be better than any of the others, monroe, gabriel, etc.